(CNN) The career of Nick Kyrgios -- who has been criticized for his attitude and on-court behavior in the past — is under renewed scrutiny after the Australian tennis star received a "pep talk" from the umpire during his match against Pierre-Hugues Herbert at the US Open on Thursday. After Kyrgios let two serves pass him by while he was a set and 3-0 down to the Frenchman and reportedly threatened to quit the match, umpire Mohamed Lahyani climbed down from his chair and said he wanted to "help" the 23-year-old Aussie. "I want to help you," Lahyani could be heard telling Kyrgios from TV microphones, "I know this is not you." Nick Kyrgios of Australia takes a break during his men's singles second round match against Pierre-Hugues Herbert on Day Four of the 2018 US Open. The pep talk had quite the effect with the world No. 30 going on to claim the set and win the match against Herbert 4-6 7-5 6-3 6-0. 'From that moment he dominated the match' However, several tennis players and commentators were quick to criticize the umpire's intervention. "I don't think this is appropriate for an umpire," 27-year-old Herbert told reporters after the match. "We don't know what would have happened if he (Lahyani) didn't do it. We're not supposed to have a coach on court," he said, suggesting that he could have won if the umpire didn't intervene. Pierre-Hugues Herbert of France says the umpire's intervention was inappropriate. "Nick from his side is not to blame as he did not ask for anything. But his behavior and motivation on court changed from this moment and then he dominated the match," Herbert said in a statement. The Association of Tennis Professionals rules that male players are not allowed to receive on-court coaching and Herbert said he believes Lahyani should be sanctioned for his actions. "If he makes a mistake, I think he should be also punished. "He doesn't make that many mistakes, I think he's a really good umpire but today I think he went over what he should have done," Herbert told reporters. Photos: The traveling life of tennis stars On the move – The global nature of the sport means that tennis stars fly to tournaments in all corners of the globe. Here, Venus Williams arrives at Beijing Airport prior to the 2008 Olympics. Hide Caption 1 of 8 Photos: The traveling life of tennis stars Crowd trouble – Negotiating your exit from international airports can be a tricky business ... Rafael Nadal is immediately bombarded by the press after touching down at Mallorca as the newly-crowned Australian Open champion in 2009. Hide Caption 2 of 8 Photos: The traveling life of tennis stars Severe delays – Long journeys can often take their toll. It took Agnieszka Radwanska 55 hours to travel from Montreal, Canada, to the Olympics in Rio. She then lost her first round match in 99 minutes. Hide Caption 3 of 8 Photos: The traveling life of tennis stars Flying the nest – The rigorous demands of the Tour mean that players spend long periods away from their homes and families. Here, Sam Stosur embraces her father in Brisbane airport, Australia, after winning the US Open in 2011. Hide Caption 4 of 8 Photos: The traveling life of tennis stars Lap of luxury – But it's not always economy class and long delays; players are also treated to private jets and five-star service. Here, Nick Kyrgios, a member of the Singapore Slammers, travels to Singapore prior to an International Premier Tennis League match in 2014. Hide Caption 5 of 8 Photos: The traveling life of tennis stars First service – And there is much to be said for good company, food and drink. Ana Ivanovic offers drinks to Jo-Wilfried Tsonga and Gael Monfils. Hide Caption 6 of 8 Photos: The traveling life of tennis stars Video game, set, match – Kyrgios (right) and Tsonga (left) have never faced each other on the Tour circuit, but they had a chance to while enjoying a pre-flight computer game alongside Frenchman Gael Monfils. Hide Caption 7 of 8 Photos: The traveling life of tennis stars Heavy cargo – In the same lounge, Novak Djokovic is pictured surrounded by players' racket bags -- a sizable piece of cargo to lug around the world. Hide Caption 8 of 8 After the game, Kyrgios said the umpire's actions didn't affect his performance. "It didn't help me at all," he told reporters. "I'm not sure it was encouragement. He said he liked me -- I don't know if that's encouragement. He was just concerned with how I was playing." 'The USTA is clearly taking us for fools' In an earlier statement the United States Tennis Association said Lahyani "left his chair to check on the condition" of Kyrgios. "Lahyani was concerned that Kyrgios might need medical attention," it said. US Open Statement from US Open Tournament Referee on the Nick Kyrgios vs. Pierre-Hugues Herbert Match pic.twitter.com/UHKPhVeYIb — US Open Tennis (@usopen) August 30, 2018 "He also informed Kyrgios that if his seeming lack of interest in the match continued, that as the chair umpire, he would need to take action." However, Herbert said he was "even more upset" about the USTA's statement and said the association is "clearly taking us for fools." "We all hear on the video what the umpire said to Nick, overpassing his functions." However as the furore grew over the incident, the USTA changed tack. "After a comprehensive review conducted by US Open officials, including US Open Tournament Director David Brewer, Tournament Referee Brian Earley and others, the US Open determined that chair umpire Mohamed Lahyani's conduct during Thursday's second-round match involving Nick Kyrgios and Pierre-Hugues Herbert went beyond protocol," said the USTA statement. "Lahyani was advised to adhere to proper protocols in all matches that he officiates moving forward. "Lahyani will continue to officiate during the 2018 US Open. His performance will continue to be evaluated, as will that of all chair umpires throughout the course of the US Open." Federer: 'A conversation can change your mindset'<doc-sep>The main interview room in the bowels of Arthur Ashe Stadium was as packed with reporters and cameramen as you’ll find it after a second-round match on an otherwise routine Thursday afternoon during the first week of the US Open. The occasion was an audience with Nick Kyrgios, the mercurial Australian star who an hour earlier had seen off the Frenchman Pierre-Hugues Herbert amid sweltering heat and humidity on the fully exposed Court 17, where after what appeared to be a public unravelling was curtailed by an unusual intervention from the chair umpire Mohamed Lahyani, who descended from his chair and entered an exchange with the world No 30 that many onlookers, particularly those privy to the intimate angles and sound captured by the television cameras and on-court microphones, was interpreted as a pep talk. Kyrgios did not appear to be giving his all in the opening stages of the match, failing to fully extend on returns of serve and appearing disinterested for extended stretches, prompting boos from the crowd over the visible lack of competitive spirit. He frittered away the first set and fell behind 0-3 in the second, which is when he received a visit from an unusual interloper. “I want to help you. I want to help you,” Lahyani said during the changeover. “I’ve seen your matches; you’re great for tennis.” He added: “Nick, I know this is not you.” For a 23-year-old who has been cast as one of the most unpredictable athletes in the world, there’s one thing you can count on: Kyrgios brings the drama. Thursday was no exception as he suddenly found himself at the centre of the US Open’s biggest story. 00:46 Controversy follows Nick Kyrgios after umpire's pep talk at US Open – video The exchange, and potential impropriety on part of the veteran official, was the central topic of conversation among the sport’s chattering class well before Kyrgios finished off the 4-6, 7-6, 6-3, 6-0 victory to book a third-round blockbuster with Roger Federer on Saturday. International Tennis Federation rules state officials must “maintain complete impartiality with respect to players at all times and must avoid any real or perceived conflicts of interest”, but the Australian was quick to deflect suggestions that Lahyani’s intervention aided him in any fashion. “I’m not sure it was encouragement. He said he liked me. I’m not sure if that was encouragement. He just said that it’s not a good look. Look, I wasn’t feeling good. I know what I was doing out there wasn’t good. I wasn’t really listening to him, but I knew it wasn’t a good look. It didn’t help me at all. Like, I was down 5-2. If it was 3-0, and maybe if I would have come back and won six games in a row, fair enough. Didn’t help me at all.” He continued, not incorrectly: “It happens in other sports, too. In soccer, if someone is being roughed, they get warned. If you keep doing this you get penalised. Same sort of thing. It had no effect at all.” Herbert was non-committal over whether Lahyani’s intervention swung the match, but he didn’t seem overly convinced that it hadn’t. “I don’t know what to think,” he said after reviewing the footage. “I don’t know if something happened, if Mohamed would have said something or not, it wouldn’t have changed anything. I cannot tell you. I just can tell you from that point Nick was playing much better. “Actually, the umpire doesn’t have to talk to him at all. The only thing he can tell him is, yeah, pay attention, because if you continue like this, I’m going to give you a warning, something like this. They can tell him from the chair. He doesn’t need to go down. He doesn’t need to say the words he said on the video. I think this was not his job. I don’t think he’s a coach, he’s an umpire, and he should stay on his chair for that.” The United States Tennis Association, which organizes the US Open, was quick to produce a three-paragraph statement attributed to the tournament referee not long after Kyrgios’ press conference which appeared to fully exonerate Lahyani. But Herbert released a subsequent statement on Twitter in both French and English saying: “I am even more upset against the statement of the USTA that is clearly taking us for fools. We all hear on the video what the umpire said to Nick overpassing his function. Err is human but I still wait for explanation.” Controversy seems to trail Kyrgios, a prodigious talent who has spent his brief professional tennis career dazzling, frustrating and bewildering followers of the men’s tour, sometimes in the course of the same match, in the uncanny, self-fulfilling way it attaches itself to provocateurs and iconoclasts in any line of work. He was 19 when he rocketed to global fame by upsetting then-world No 1 Rafael Nadal to reach the Wimbledon quarter-finals in 2014. He’s one of only two players to pick off Nadal, Federer and Novak Djokovic in their first meetings. This summer he became the youngest player on the circuit to earn wins over all of the Big Four. Yet so often he’s followed up signature triumphs with the sort of desultory, self-sabotaging efforts like the start of Thursday’s match, which invite public concerns over his commitment to conditioning and professionalism. He airs his dirty laundry and spars with journalists on Twitter. For years Kyrgios has been the kid with the C-plus average, more than capable of capturing lightning in a bottle on the day but lacking the consistency to put his stamp on the sport’s four bedrock events. Few athletes in recent years have been subject to more pop-psychological analyses, but here’s one more: you can’t help but wonder if there’s a fear of putting it all on the line if only because it might not be enough. Those concerns are valid, yet it makes for compelling theatre. And there is a strange hypocrisy in the broader flagellation of Kyrgios, one led by the ravenous Australian media corps but echoed globally.<doc-sep>Nick Kyrgios is no stranger to controversy on the tennis circuit, and the Australian star had his latest incident on Thursday at the US Open. After dropping the first set of his second-round match against Pierre-Hugues Herbert, Kyrgios basically stopped trying. He didn't even try to hide it either; he just kept allowing Herbert to blow serves by him without even attempting to return them. This isn't exactly a new issue for Kyrgios, who has a reputation of being somewhat of a headcase who has issues with effort and focus. Earlier this month, he conceded that he tanked intentionally during the Cincinnati Open. His lack of effort and passion for his craft has been a sore spot for a lot of tennis fans, especially since Kyrgios' talent is undeniable. Many believe if he could put it all together and just commit to the game, he'd be one of the best players on the planet. It's just a matter of getting him to commit. On Thursday, it was chair umpire Mohamed Lahyani who tried to implore Kyrgios to use his talents and start showing a little effort on the court. Lahyani got down from his post in between sets and attempted to give Kyrgios a pep talk. It was truly a bizarre scene for a Grand Slam event, and one that had a lot of people wondering whether the umpire is within his right to do such a thing. It turns out he might not be. If Lahyani gets in trouble for his actions on Thursday, maybe he should consider moving from the umpire chair to Kyrgios' coach's box. Not only did Kyrgios turn around and win the second set following Lahyani's pep talk, he also won the next two sets (and in pretty dominant fashion) to advance to the third round.<doc-sep>Seth Wenig/Associated Press The United States Tennis Association is reportedly looking into the actions of chair umpire Mo Lahyani after he appeared to give a pep talk to Nick Kyrgios during his second-round match at the 2018 U.S. Open on Thursday. Kyrgios, who is prone to meltdowns, appeared to be having another one in the second set against Pierre-Hugues Herbert. He allowed multiple serves to blow past him without any effort as he dropped to down 0-3 in the second set after losing the first. "I want to help you, I want to help you. ... I've seen your matches, you're great for tennis," Lahyani told Kyrgios, per Ben Rothenberg of the New York Times. "... I know this is not you." The pep talk appeared to work. Kyrgios came back to win the second set 7-6 (6), and he went on to a 4-6, 7-6 (6), 6-3, 6-0 victory over Herbert to advance to the round of 32. "He was just concerned about how I was playing. He was like, 'Nick, are you OK?'" Kyrgios said after the match. "I was like, 'Yeah, everything is fine.' I just wasn't feeling great." Kyrgios has a history of giving up on matches. He admitted to having given up at a certain point in his match against Borna Coric at this month's Western & Southern Open. Like he did Thursday, Kyrgios eventually came back from his funk and won the match against Coric.<doc-sep>
A chair umpire at the U.S. Open appeared to give Nick Kyrgios words of encouragement after he stopped trying on his way to losing the first set of a match. After what some have called a "pep talk," Kyrgios went on to win the second and third sets. Many in the tennis world raised their eyebrows at the exchange and criticized the umpire for speaking to a player directly. A bizarre scene unfolded at the U.S. Open on Thursday during a second-round match between 30th-ranked Nick Kyrgios and Pierre-Hugues Herbert. The occasionally temperamental Kyrgios appeared to stop trying during the first set, failing to even move while Herbert served. Herbert won the set, 6-4. After the set was over, the umpire, Mo Lahyani, got off the chair and went over to Kyrgios, appearing to offer him words of encouragement. According to tennis reporter Ben Rothenberg, Lahyani could be heard saying things like "I want to help you," "You're great for tennis," and "I know this is not you." Singles tennis is just that — players don't receive outside help. It's unusual to see an umpire address a player without doing so through the microphone. Here are the plays that preceded what some are calling a pep talk where Kyrgios stopped trying: And the discussion between Lahyani and Kyrgios: Kyrgios went on to win the second, third, and fourth sets to win the match. Plenty of others in the tennis world raised their eyebrows or flatly criticized Lahyani for his actions, including Rothenberg, who called it "insane" and called for Lahyani to be pulled from the match. Later on Thursday, the U.S. Open put out a statement, explaining the interaction between Lahyani and Kyrgios.