( CNN ) -- Ernests Gulbis is no stranger to a controversial comment . The Latvian tennis star once described the press conferences of Roger Federer , Novak Djokovic , Rafael Nadal and Andy Murray as boring . Then there was the time he said the fact that marijuana was legal in the Netherlands was one of the reasons he liked playing in Rotterdam so much ( although he quickly added that he did n't smoke himself , he just liked that way of thinking ) . Now , Gulbis has caused a stir thanks to his views on the sport 's female players , telling reporters at the French Open in Paris he hopes his younger sisters do n't become tennis professionals because women need to think about having children . `` Hopefully they 're not going to pursue a professional tennis career , '' Gulbis said . `` A woman needs to enjoy life a little bit more , needs to think about family , needs to think about kids . '' He added that female tennis players ca n't think about having kids until they are in their late 20s , and `` that 's tough for a woman . '' Unsurprisingly , Gulbis ' comments were picked up on social media sites Friday with many decrying the remarks as sexist . But Maria Sharapova , who defeated Paula Ormaechea 6-0 , 6-0 Friday to move into the fourth round of the ladies draw , played down any controversy . `` I do n't think we can take everything serious when he speaks , '' Sharapova laughingly said in her post match press conference . `` I think he 's great entertainment and we love to listen to what he has to say . '' `` I think the sport brings so many opportunities to women . I mean , it 's brought me so many things into my life and my career . I do n't regret any step that I have taken . '' Gulbis was speaking after defeating Radek Stepanek of the Czech Republic 6-3 , 6-2 , 7-5 . He now advances to play Roger Federer in the fourth round after the Swiss overcame Dmitry Tursunov 7-5 6-7 ( 9/7 ) 6-2 6-4 . Gulbis , who has risen to a career high world ranking of 17 thanks to a fine run of form this year , has never made the fourth round of a major before but admitted he was keen to make up for lost time . `` Until the last two years I would be consistent for say three months , then I got sick or went to Latvia and took stupid ten days off , '' he said . `` Now I 'm jumping on the last train . I 'm 25 so this is my last opportunity to be really successful . '' Gulbis and Federer were joined in the fourth round later in the day by world No 2 Novak Djokovic who battled past Croatia 's Marin Cillic 6-3 6-2 6-7 ( 7-2 ) 6-4 . The Serb , who dropped a set against Cilic for only the third time in nine meetings , will now face home-favorite Jo Wilfred Tsonga for a place in the quarter finals . `` Physically I had to work very hard , because he was very aggressive , and I could expect that , '' Djokovic said of his opponent after the match . `` ( But ) In important moments I held my nerves and , you know , I 'm very happy that I went through . '' Elsewhere in the men 's draw , John Isner overcame Tommy Robredo of Spain 7-6 ( 15-13 ) 7-6 ( 7-3 ) 6-7 ( 7-5 ) 7-5 . The big-serving American will now meet Thomas Berdych in round four after the Czech beat Spain 's Roberto Bautista Agut . Radwanska stunned . The women 's draw witnessed yet another shock Friday as third-seed Agnieszka Radwanska lost to unseeded Croat Ajla Tomljanovic . The Pole went down 6-4 6-4 in the first game of the day on Philippe Chatrier and follows top seeds Serena Williams and Li Na in making an unexpected an early exit at Roland Garros . `` After seeing the two first seeds go out , ( I ) feel like I can do this too . I grew up with these girls that are beating them ... obviously , you respect everyone , but you do n't fear anyone , '' Tomljanovic told reporters . The highest ranking player left in the ladies competition is now fourt seed Simona Halep of Romania who does n't play her third round match against Maria-Teresa Torro-Flor until Saturday . Elsewhere on Friday , Angelique Kerber of Germany beat Slovakia 's Daniela Hantuchova 7-5 , 6-3 and will now face 18th seed Eugenie Bouchard of Canada for a place in the quarters . Meanwhile , Samantha Stosur overcame Dominika Cibulkova 6-4 , 6-4 to set up a fourth round tie with Maria Sharapova .
Ernests Gulbis says female tennis players need to think about kids when considering careers . Female tennis players ca n't have kids until late teens and ` ` that 's tough '' she said . Maria Sharapova tells reporters not to take Gulbis too seriously .