Ryan Giggs's right to have a testimonial when he is already a millionaire has been defended by the Professional Footballers' Association.

Giggs, who this summer signed a five-year deal with Manchester United worth around £50,000-a-week, could pocket over £1 million tax free from tonight's sell-out game against Celtic at Old Trafford.

The 67,500 attendance will eclipse the 57,268 who turned out for Celtic defender Tom Boyd's testimonial at the end of last season when United beat the Scottish champions 2-0 and Giggs's benefit match is set to be the most lucrative in British football.

PFA chief executive Gordon Taylor claims if the fans did not agree with Giggs having a testimonial, then they would not have bought tickets.

"The fact that it is a full house gives you your answer," he said.

"The supporters can choose with their feet and they have chosen to pay tribute to Ryan's loyalty to Manchester United.

"It seems players can't get it right and on the one hand they are accused of being mercenaries if they want to walk out on a club and if they remain for a period and give 10 years' service, people still go on about them.

"Whether it's justified financially is open to question, but from that point of view it's a short career. In the world of business, directors get share options and everything else.

"Ryan has contributed a great deal to Manchester United over the last 10 years and this is the supporters' way of saying thank you."

United manager Alex Ferguson agrees with Taylor and he feels the 27-year-old Welsh international fully warrants a testimonial because of his 10 years' service to the club.

During that decade Giggs has helped United win 12 major trophies and he is the most decorated member of the current squad alongside Denis Irwin.

Ferguson said: "Some people say that players don't deserve testimonials any more, but I think Ryan does. It is the first benefit for one of our home-grown players, who came through in that new era in the early to mid-90s."

The match, which will be the second leg of United's 'Battle of Britain' with Celtic, has been eagerly anticipated by United fans because it will be their first chance to see new signings Juan Veron and Ruud van Nistelrooy.