Wimbledon title-rival Roger Federer says he's pretty sure defending champion Andy Murray will be in contention at the All England Club.

The world number one's pulled out of an exhibition today with a hip problem.

Murray's only played one competitive grass-court match ahead of the Grand Slam - and that was a first-round defeat at Queen's.

But Federer says he expects him to be in form when it gets underway.

"For him, the most important thing is to get through the first week," he said. "The positive thing for him is that he's a good first week player.

"He doesn't mind the slippery grass or the bounce of the ball on the courts. He might even thrive in these conditions."