SHANGHAI (AP) -- Despite Roger Federer's recent drop in play, Rod Laver thinks the Swiss star is still the greatest player of his generation.
Laver, the only tennis player to achieve the Grand Slam twice, said Federer's consistency over the six to eight years at the top is what sets him apart from contemporaries such as Rafael Nadal and Novak Djokovic.
''When I look at Federer, with what he's accomplished, against the competition that he's accomplished it with, I'd have to say I would think that Roger is the greatest player,'' Laver said Thursday at the Shanghai Masters.
The Australian won the Grand Slam in 1962 and 1969. He remains the only man to have won it in the Open era, which started in 1968, but was quick to add he's not sure he can call Federer the greatest of all time.
''I've always said if you're the best in your era, that's as good as you really can do. You could take it back to 'Is it Fred Perry, is it Don Budge, is it myself that came along?'''
Laver, who made his first trip to China to attend the Shanghai Masters, sat courtside as Federer lost in the third round to Gael Monfils of France 6-4, 6-7 (5), 6-3.
He said before the match that he can empathize with the trouble Federer has had staying near the top of the game and contending for majors at age 32.
Laver recalls when he reached his 30s, he could play excellent one day and have nothing left the next.
''Is it the desire? Is it your emotion, does it come up? Is your adrenaline not flowing as well as it normally does in a match?'' he asked. ''I don't know whether Roger's feeling anything of that nature. But sometimes I notice him, he just doesn't have it that day. But the day before he was magnificent.
''So it's not a training method, fitness, nothing to do with his body. So, you know, you just wonder, is it adrenaline that gets you up for matches?''
As for who can match his feat of winning a Grand Slam, Laver is now looking at Nadal.
Many men have been close to the Grand Slam by winning three of the four majors, including Federer (2004, '06, '07), Nadal (2010) and Djokovic (2011), but none has been able to capture all four in a single season.
''When I look at the way Nadal plays on grass, clay and hard courts, especially this year, he's obviously one that can win it,'' Laver said. ''The only reason why Federer didn't win a Grand Slam was because of Nadal on clay.''