FA Community Shield: Daniel Taylorwonders how long  Manchester United legend Ryan Giggs can keep newcomers at bay as he starts his 18th season at the club

He was the boy who played like a man and now he is the man who plays like a boy. The question for Ryan Giggs is how long can he remain at the top. Manchester United's longest-serving player is approaching an age when insecurity can appear on a footballer's horizon and, as he embarks on his 18th season at the club, the Welshman may be confronted by one of the biggest challenges of his illuminating career.

Ferguson speculated this week that Giggs, 34 in November, could carry on playing at the highest level for another three years and, given the player's outstanding professionalism, there is no reason to believe this to be an exaggeration. Yet Ferguson has just embarked on a summer spending spree that has brought in, among others, Nani, Anderson and, imminently, Carlos Tevez.

What Ferguson did not make clear was whether he envisaged Giggs consolidating his status as a mandatory first-team pick or becoming simply a squad player. Ferguson has spoken about Nani being "for the future", but for how long can Giggs keep out this extravagantly gifted Portuguese winger?

Those who are closest to Giggs say he is aware of the threat and determined to meet it head-on, starting tomorrow when he is expected to captain United in the Community Shield against Chelsea. He is lithe and agile and has not lost much of the pace that once led Gary Pallister to remark that the Welshman left defenders with "twisted blood".

With the passing of time, there is also evidence that Giggs's distribution has improved and he has become increasingly aware of how to create space for others. Roy Keane says there is no better trainer at Old Trafford and, in any debate about Giggs's longevity, it is important to note he is also blessed with the heightened level of self-belief that is essential for all top sportsmen.

An insight into Giggs's character can be gleaned from a story Gary Neville tells about when Ferguson signed another left-winger, Jesper Blomqvist, in 1998. Some of the older players started winding up Giggs, joking that the writing was on the wall for him. Giggs, one of the sharpest-witted players at Old Trafford despite his occasionally dry interview technique, took it all in good humour. But at the end of it all, he turned to Neville, looked him in the eye and said matter-of-factly: "He'd better be good."

Blomqvist could seldom get past Giggs and usually had to rely on his colleague's intermittent hamstring problems for an extended run in the United first team. Park Ji-sung arrived in 2005 and the South Korea international, too, has discovered that Giggs is not the type to accept that Ferguson has plans for the team that do not involve him.

"The thing about Ryan," says Ferguson, "is that there is nobody else in the game who has done what he has done. He has been up and down that wing for 15 years, and nobody else in the country has done that. He looks after himself terrifically and he has always been blessed with great natural fitness. He can go on, mark my words."

There is, however, a gentle phasing-out of the club's thirtysomethings under way and Giggs could conceivably find his chances more limited this season than last, when he made 44 appearances. Ole Gunnar Solskjaer will turn 35 next February and intends to retire at the end of the season.

Anderson, the 19-year-old Brazilian midfielder signed from Porto, has been recruited with a view to replacing Paul Scholes and the former England international, who will be 33 in November, is likely to play a more conservative midfield role this season, dropping into advanced positions rather than the box-to-box role of old.

Gary Neville, another 32-year-old, has improved with age and is quite possibly the best crosser of the ball at Old Trafford, but Ferguson also intends to keep a close eye on the England defender to check for signs of deterioration.

As for Giggs, he needs to make another 38 appearances before he takes Bobby Charlton's record of having played in more games (755) than anybody else in the club's history.

That time will surely come at some stage but it may not necessarily be this season and, starting at Wembley tomorrow, United's brilliant number 11 knows that he is going to be under close scrutiny.