John Isner, better known for taking more than 11 hours to win a Wimbledon match in 2010, leads American hopes at the French Open of ending an agonising 33-tournament wait for a Grand Slam men's title winner. But if history is any guide, Roland Garros, which starts on Sunday, is unlikely to break that streak. Andre Agassi was the last American to win the men's crown at Roland Garros in 1999. He was also the last US player to get as far as the quarter-finals in 2003. The mantle then passed to Andy Roddick, his country's last major winner when he lifted the 2003 US Open. But Roddick, who missed the 2011 French Open with a shoulder injury, is no longer America's top player, and is now at 29 in the world after slumping to an 11-year low of 34 in March. A hip injury kept him off tour for two months and his return to action in Dusseldorf this week at the World Team Cup saw him lose twice in straight sets to Carlos Berlocq of Argentina and Czech top 10 player Tomas Berdych. "I don't think you expect to come out after a lay-off and play great," said Roddick, 29, after his season claycourt bow. Mardy Fish is the American number one player but the 30-year-old hasn't played since a first round exit on clay in Houston six weeks ago and had already said he won't be in Paris due to illness. His best Roland Garros showing remains a run to the third round last year. That leaves US hopes in the 2.06m frame of world number 11 Isner who took six-time champion Rafael Nadal to five sets -- having held a two sets to one lead -- in the 2011 first round. But Isner, who famously took 11 hours and three days to beat France's Nicolas Mahut at Wimbledon in 2010, has endured a roller-coaster season on clay. The 27-year-old began by beating Roger Federer in the opening round of the Davis Cup, before leading the US to a quarter-final win over France -- seeing off Gilles Simon and Jo-Wilfried Tsonga -- on Monte Carlo's famous clay courts. That was followed by a runners-up spot in Houston, when he briefly became national number one, and the signs looked good for American claycourt hopes. But Isner's return to Europe has been beset by familiar problems with an opening loss in Madrid to Marin Cilic followed by a second round exit to Andreas Seppi in Rome. "I like playing on clay," insists Isner. "(This year) my best wins have come on clay. It's a surface I enjoy playing on and a surface I feel I can do very well on." Davis Cup skipper Jim Courier, who won back-to-back French Opens in 1991 and 1992, believes Isner can be a surprise package at Roland Garros. "(Against France) he was exceptional. He is continuing to progress," said Courier.