Manchester United legend Ryan Giggs celebrates his 40th birthday

Ryan Giggs has dismissed the relevance of age to his career as the Manchester United legend celebrates his 40th birthday.

The Welshman turns 40 on Friday and Giggs remains an integral member of United's playing ranks, despite also taking up a coaching role in the summer following David Moyes' appointment.

He sparkled in central midfield during United's 5-0 thrashing of Bayer Leverkusen in the UEFA Champions League in midweek in a performance which showed how Giggs has developed as a player since he burst onto the scene as a buccaneering winger in the early 1990s.

Giggs does not believe age should factor into any thoughts of retirement and his priority is ensuring that he can still make a positive contribution to United.

"There is an ageism thing but I just take it as a challenge. I will now myself when it is time. The thing you have to come to terms with is people saying, 'His legs have gone, he shouldn't be in the team because he is too old'. But I had bad games when I was 19, 20 or 25, 26, probably more in fact. You just have to weigh up are you still effective, are you still contributing, is the manager still picking you?"

Ryan Giggs

"There is an ageism thing but I just take it as a challenge," said Giggs. "I will know myself when it is time.

"The thing you have to come to terms with is people saying, 'His legs have gone, he shouldn't be in the team because he is too old'.

"But I had bad games when I was 19, 20 or 25, 26, probably more in fact. You just have to weigh up are you still effective, are you still contributing, is the manager still picking you?"

There has been talk of a new one-year contract for Giggs and he concedes that he would not still be playing if he had ever left Old Trafford.

"If I'd moved from club to club I'd be finished by now," added Giggs. "I'm lucky that I have been at one club, where I am surrounded by good players. I also have a good manager.

"I look after myself and try to train every day in order to make myself available for selection.

"I enjoy it as much as I can and, of course, try to contribute to the team."

His former United team-mate David Beckham led the tributes, saying Giggs was the player the young stars admired.

"He was someone that we looked up to, he was only a year or a couple of years older than us but he was someone that we aspired to be because he was a young player in the first team playing like he was, so talented and at a very young age. That gave the rest of the youth team players hope."

Gary Neville interviews Ryan Giggs. Sign in to Skysports.com or go to the Sky Sports ipad app for an extended version.

Giggs' team-mate Wayne Rooney, meanwhile, says he struggles to find superlatives for United's record appearance holder and doubts he will still be playing when he turns 40.

"I've run out of things to say about Ryan," Rooney said.

"Actually, during the game, the Bayer centre-half was asking how he is still playing at that age.

"I certainly won't be playing at that age, that's for sure. His composure on the ball is great."

David Beckham explains how he and the rest of the Manchester United youth squad looked up to Ryan Giggs

Chris Smalling believes that Giggs is a great example for the players and praised his contribution during the win over Leverkusen which secured United's place in the last 16 of the Champions League.

"Ryan is a role model for us all," said Smalling. "He is a cool head in the middle.

"Despite his age, even in the 90th minute he was still taking on three or four players.

"It is terrific to see such a legend playing amongst us.

"His pass for Nani's goal at the end just sums him up. He has that incredible vision. He is terrific and an example to everyone."