Written last year but the points cash makes are still relevant. Interesting read. Pat Cash questions Federer quality When The Sunday Telegraph contacted the 44-year-old last week for his thoughts on the Australian Open, Cash was as honest and forthright as ever. He declared the legacy of Swiss legend and world No 1 Roger Federer won't be known until he has weathered the storm he is set to face over the next three years. It's almost blasphemy in the world of tennis to question Federer's greatness, but that didn't deter Cash. "The next couple of years is the only time he will have been challenged by more than one person," Cash said. "(Rafael) Nadal has a winning edge over him and he has it over him mentally, too. "I think (Juan Martin) del Potro and Andy Murray are really troubling him lately and I just hope we haven't seen Federer peak when there weren't any challenges." Pete Sampras, who saw Federer go past him at Wimbledon last year when he claimed his 15th Grand Slam title, was defined by his rivalry with Andre Agassi. Before that, it was Bjorn Borg, John McEnroe and Jimmy Connors. And in Cash's day, he battled the super Swedes, Mats Wilander and Stefan Edberg, and Ivan Lendl. For much of his career, Federer was playing against history - trying to chase down Sampras's 14 Grand Slams. Now that he has got there, the rivals are real - and they are coming to get him. "It doesn't really make it a fair indication of how good he really is if there hasn't been anyone really to challenge him," Cash said. "It will almost be a false impression of how good he really is. "But I think over the next few years we'll see how good he really is. You've got to look at who you play. You can't just put a man in a boys' tournament and say, 'Wow, how good is he?' "Because suddenly you drop another man in there and think, 'He's not as good as we thought he was'. And at the moment for me, that's what is still in question." THE BATTLE Federer has appeared in an unprecedented 21 Grand Slam finals and has reached the semi-finals or better of the past 22 major tournaments. It is a record streak that spans five years. He also holds the record of reaching 10 consecutive Grand Slam finals and has appeared in 17 of the past 18. And the world No 1 has won 16 ATP Masters Series tournaments, one less than Agassi's record. But, according to Cash, tennis fans should mark down the Australian Open of 2010 as the year the onslaught began. "Because it was a bit of a one-horse race, then a two-horse race for so long. But now I think this is a legitimate challenge there for Federer," Cash said. "Federer really was in a league of his own for a while, partially because he's so good. He brought a different aspect to the game, but a lot of players have become accustomed to his style now and they have worked him out. "It's going to be not so easy for him any more. "He's a sensational player and he'll continue to win big tournaments, for sure, but I don't see it as quite as freely. Nadal was injured last year, so you've got to say Federer had a bit of luck in the French Open. "Federer's amazing because he's so fit. He stays in incredible shape all the time. There's no doubt his shot-making is one of the greatest of all time, if not the greatest. But it's easy to make shots when you're not playing against anybody of your standard. "Now he's got other players of his standard, so, I think it will be a great challenge for him and hopefully he can stand up to it and stay fit as well." THE RIVALS In 2001, Cash lost a claycourt exhibition match to a then 15-year-old Nadal. He knows the Spaniard well and believes only a nagging knee injury robbed the world No 2 of solidifying the pressure on Federer. But it's Argentine giant Juan Martin del Potro who really excites Cash. The former Australian Davis Cup hero suggested the world No 4 has the high-powered game to bring down Federer, just like he did in last year's US Open final. "I think del Potro is a very, very good player. I heard he hurt himself this week so hopefully he'll be OK," Cash said. "I think he's a real superstar. "I think Andy Murray is a real superstar, also (Novak) Djokovic has a lot of potential as well. He's a real danger player. So there's a handful now." The new wave will get their crack at the master this week at the Australian Open. Last year, it was Nadal who brought down the Swiss maestro. This year, the world No 1 is facing an ambush.