Ryan Giggs
Manchester United's Ryan Giggs celebrates his goal against Benfica during the Champions League Group C soccer match at the Luz stadium in Lisbon.

Manchester United midfielder Ryan Giggs will carry on playing for as long as he is making a contribution to Sir Alex Ferguson's side.

The evergreen Welshman remains a hugely impressive and influential figure for the defending Premier League champions, despite his 38-years of age, and although he has often been championed as a one off in the modern game, Giggs believes there will be plenty more Premier League players extending their careers into the late 30s given the strides made in sports' science.

The most decorated player in Premier League history suggests his remarkably playing career will only be curtailed by a lack of motivation and his diminishing ability, intimating day-to-day training at Manchester United keeps him young.

"You have to remain motivated, otherwise you get swept away," The Manchester United icon told the Manchester Evening News. "You have to raise your game or you are not contributing and become a waste of time. It's not just about performing in games but also in training.

"You have to keep going up a level, no matter what age you are."

The recent return of Paul Scholes has perhaps highlighted Giggs' desire to continue playing, claiming he is no rush to set a retirement date, given his continued influence on the Manchester United first team.

"I don't know how long I can keep playing for," added Giggs. "As long as I am enjoying it and still contributing to the team, not making a fool of myself in training or games. I still want to perform and I still want to enjoy it.

"If you are not playing well or feel you are coming up short in training, that is the time to hang up your boots."

Teddy Sheringham was 95-days shy of his 41st birthday when he played his final game for West Ham in the Premier League, but Giggs, who is 39 in November, believes footballers could soon be playing well into their 40s.

The Manchester United hero concluded: "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,"

Giggs has regularly credited his longevity at Manchester United down to yoga, which he has been practicing since 2009.