MONTREAL ? Roger Federer and Rafael Nadal return to tennis after long absences Monday at the Montreal Masters with top seed Federer playing just three weeks after the birth of his twin daughters.
The Swiss is happily on a roll after winning both the French Open for the first time and Wimbledon for the sixth.
Nadal's story is a polar opposite as the Spaniard has been forced to rest his tendinitis-plagued knees for nearly two months after being forced out before Wimbledon due to the injury and being deposed as French Open champion.
Neither man can predict the outcome at the first major event since Wimbledon ended five weeks ago, when Federer moved deeper into the record books with his 15th Grand Slam title, earned at the expense of Andy Roddick.
Nadal went through what looked to some an uninspiring training session after arriving in Canada following weeks at home on the island of Mallorca with his practise time extremely limited.
The Spaniard is set to defend the title he won last year at the event which alternates between Toronto and Montreal in the English and French-speaking parts of Canada.
But Nadal is making no promises at all as to how his game will shape up given the chronic state of his knees and the obvious confidence blow which now besets his athletic game.
"I'm aware that I am going to Montreal and Cincinnati to lose. It's logical," he said prior to departure. "I'm not sure about my level on the first tournament. I'm even not sure if I will have pain again."
Nadal last competed on May 31 when he lost to Sweden's Robin Soderling in the fourth round of the French Open, his first career defeat at the tournament which he won four times in succession.
The top eight seeds all have byes, with the elite not set to open before midweek.
Briton Andy Murray, fresh off a week or more of training at his base in Miami, takes the third seeding and could surpass Nadal should the Spaniard's form fail to gell.
Serb Novak Djokovic, still searching for a major title since winning the Masters Cup to end last season, is seeded fifth ahead of Wimbledon finalist Andy Roddick and Argentine Juan Del Potro.
Frenchman Jo-Wilfried Tsonga stands seventh with compatriot Gael Monfils 13th and set to play for the first time since June 10, ready to test his knee problems with an opening match against Marat Safin.