John McEnroe has tipped Britain's Andy Murray as one of a group of young players who are capable of breaking into the world's top 10 next year.
Murray has rocketed up the rankings this season
The 18-year-old Scot has enjoyed a breakthrough season, moving from outside the world's top 400 to 65.
"Andy Murray, Tomas Berdych, Gael Monfils and Nenad Djokovic - one of these guys is going to break into the top 10 next year," said McEnroe.
"A couple of them will hang around there and that will be interesting."
McEnroe said the crop of young talent could have a better chance of challenging Roger Federer than the other top players currently in the world number one's shadow.
"The young guys may have a better chance of hurting Federer because they don't have any fear," he added.
"Rafael Nadal has made huge steps, but can he keep that level?
"Andy Roddick has perhaps taken a step back, Lleyton Hewitt has a whole new set of issues with being a dad and Marat Safin is totally questionable.
"Maybe David Nalbandian, if he retains his fitness, can win a major. But maybe it will be one of the new guys that breaks out and makes an impact."
The 46-year-old, in London to take part in the Masters tournament at the Royal Albert Hall alongside the likes of Pat Cash, Jim Courier and Henri Leconte, also paid tribute to Federer's incredible year.
Federer's defeat against Nalbandian last week meant he ended the season just one win short of equalling McEnroe's incredible 1984 record of 82 wins and three defeats.
"Roger has had a phenomenal year - but while it would have been nice to be tied with him it is cool that I still have one record," said McEnroe.
"It puts in perspective how good my year was in 1984, that he put in that sort of effort when he probably shouldn't have played.
"He got through to the final but he looked like a human being for once rather than the greatest player that ever lived!"
McEnroe said Nalbandian's win could give an important psychological boost to the players chasing Federer.
"If this continues to be a problem he's going to have a really tough time. Even if he's healthy, people are going to start digging deeper to play against him," he said.