Arsenal chairman Peter Hill-Wood said the Gunners will have to strengthen their squad if they want to maintain a challenge for the Champions League.
Hill-Wood says he has no regrets over Patrick Vieira's sale
"What we've got is two or three players who are probably a year from not being good enough in the Champions League," Hill-Wood told the Daily Star.
"And to replace them immediately is incredibly difficult.
"Robert Pires, Freddie Ljungberg, Sol Campbell. Whether they have lost a yard of pace I don't know."
The Gunners face Real Madrid in the last 16 of this year's Champions League after qualifying impressively, finishing top of Group B.
But they have struggled in other competitions, stuttering in the league and losing in the Carling Cup semi-finals to Wigan.
But Hill-Wood said he backed manager Arsene Wenger to make the right decisions in the transfer market.
"Arsene's basically spent, since he's been with us, £4m to £5m a year net," said Hill-Wood.
"It's tidy money. It's distorted in a way by the £25m we got from Real Madrid for Nicolas Anelka, but he's very sensible when it comes to spending on players."
Hill-Wood backed Wenger's decision to sell former skipper Patrick Vieira to Juventus for £13.7m in the summer of 2005.
"I don't regret Patrick being sold. We didn't do it for the money," said Hill-Wood.
"I think Arsene felt Patrick almost every year was tweaking his tail and that if he did it again he wasn't prepared to suffer it."