Now is the time when United get very serious, says Rooney United launched on a tough sequence of fixtures - which even manager Sir Alex Ferguson admits will determine their prospects of silverware this season - with Sunday's excellent 2-1 win at Arsenal. Next up they head to Rooney's native Merseyside to face Liverpool in the FA Cup fourth round on Saturday lunchtime, knowing they will shortly host Kenny Dalglish's side back at Old Trafford in the Premier League, with trips to Chelsea and Tottenham either side. Trailing the leaders Manchester City by three points, it seems a tough ask of Ferguson's men just to stay in contention. However, now in his seventh season with United, Rooney has been around long enough to know it is also the time of year when they tend to reach their peak. "We relish this part of the season," he said. Once we get into the new year we can see a bit of light at the end of the tunnel. Every game is massive and we don't want to be dropping points. But I always feel we are at our best around now because we can see the end of the season and that there are trophies there to be won. That's why we stay focused. If there is an advantage for United, it is that they are in the middle of an unusual spell of playing just one match a week over a three-week period. Providing they do not draw at Anfield, that will become four out of five - they host Stoke next Tuesday - which Rooney feels could turn out to be a massive benefit for a squad that have been battling such a big injury list for so long. "It's been quite an unusual period in that we've only had one game a week," Rooney said. We have got some good training in, and that will benefit us going into the next few games. A trip to Liverpool is always a test for Rooney, who was introduced from the bench during the stormy Premier League clash between the north-west rivals in October that is best remembered for the racism row between Patrice Evra and Luis Suarez. That selection decision is unlikely to be repeated by Ferguson this weekend, even though the striking department is one area of the field where the United manager has a few options. Rooney will certainly want to be involved. For, as he pointed out, the highest-profile matches are the games that give the biggest thrill. "They are all difficult games but these are the matches you want to play in," he said. The next three or four weeks will be exciting. We understand and know what we have to do. It is widely anticipated that Nani will be ruled out with a foot injury, leaving Ferguson with just one orthodox winger. The availability of Phil Jones may counter-balance that setback, though, with United officials crossing their fingers that the teenager can shrug off the ankle injury that forced him to be substituted at the Emirates Stadium. Ryan Giggs, meanwhile, believes there will be more Premier League players extending their careers into the late 30s and beyond due to the rapid advancement in sports science. A long-time practitioner of yoga, Giggs is heading towards his 900th United appearance and even though he has passed his 38th birthday, there is an increasing likelihood he will sign another contract extension for next season. "I don't think 50 but you will probably find a lot more players in their late 30s or even their 40s if they look after themselves," the veteran Welshman said. The great unknown for any player is their inner desire to keep pushing themselves through every pre-season - which even Giggs admits can be a struggle - and every training session so that they can deliver on matchday. And, a bit like Ferguson himself, Giggs gets that desire from the challenge presented by an ever-growing list of younger team-mates. It is one of the reasons why Giggs cannot put a date on his retirement, especially now Paul Scholes has returned, having decided coaching does not fulfil him in anything like the same manner as being on the pitch for real. "I don't know how long I can keep playing for - as long as I am enjoying it and still contributing to the team, not making a fool of myself in training or games,"he said.