JOHN McEnroe believes Andy Murray's chances of winning a Grand Slam are receding with each passing tournament.

The three-time winner of Wimbledon's singles event has seen Rafael Nadal, Roger Federer and Novak Djokovic share 28 of the last 29 major titles and although he thinks the gap between them and the Scot may not be as big as some suggest, he does feel the task of becoming the first Briton since Fred Perry in 1936 to win Wimbledon isn't about to get any easier.

The ESPN pundit's comments were borne out by the draw, with big hitters such as Ivo Karlovic, Milos Raonic, Kevin Anderson and Juan Martin del Potro all likely to stand in Murray's way to what could be a third successive semi-final against Nadal.

"Murray's got himself in that type of condition that he can deal with almost anyone except these guys, and he played for five hours with Djokovic in Australia," McEnroe said.

"He's been in three finals. It's hard to tell how much it's got in his head, how discouraged he is, how close he really thinks he is, how big the gap is. It might not be as big as it appears to be. But it seems like as each event goes by, the pressure is ramped up, and it seems less likely for it to happen because he's the same age as Djokovic, and only a year younger than Nadal.

"I don't know how well he's meshing with [Ivan] Lendl as far as the coaching situation, if this is something that takes time or it's not working out as well. It's hard to say what's going on. Obviously the results haven't been that great. But let's face it, the French was always a long shot for him. This will be the real test to see if he's able to bridge the gap."

Federer comes into the event on the back of a loss to veteran Tommy Haas in Halle, but McEnroe fancies him to equal Pete Sampras' record seven victories at Wimbledon.

"I'm picking him to win this year, even though it looks like the gap has grown between the other two [Nadal and Djokovic] and him. But to me Wimbledon is his best chance to win another major. He seems to still want it as much. I think he's got a great chance."

Stewart Fisher