NEW YORK, SEPT. 8 -- Boris Becker says a tough week at the U.S. Open, a sore ankle and pressures building throughout the year have taken a heavy toll on him.

Becker's point was illustrated Monday when 13th-seeded Brad Gilbert came from behind to beat him, 2-6, 6-7 (4-7), 7-6 (7-4), 7-5, 6-1. The fourth-round loss left Becker contemplating problems he's faced since emerging as a teen phenomenon of tennis.

"I was just simply tired," the two-time Wimbledon champion said. "After a while, it's going to get in your bones . . . Everybody was just waiting for a mistake, for the losing matches. The pressure was just too much."

Becker traces his problems to the Australian Open in January, when he had a falling out with his former coach, Gunther Bosch.

The two split after Becker was eliminated from the tournament. Bosch criticized Becker's behavior. Becker accused Bosch of deserting him.

Becker's problems continued after he moved to Monaco to live with his girlfriend. He was accused of trying to avoid military service and German taxes.

"Everybody was just waiting for a mistake, for the losing matches. The pressure was just too much."

He failed to defend his Wimbledon crown this year, falling to Australian Peter Doohan in the second round.

And in the first round of the U.S. Open last week, it looked like he might make another early exit. He lost the first two sets to Tim Wilkison and faced a personal challenge -- trying to come back from a two-set deficit for the first time in his professional career.

But he did it, winning the match 4-6, 4-6, 7-5, 6-4, 6-2. He then beat Jonathan Canter in straight sets and overcame a sprained ankle to get by Andrew Castle of Britain.

Finally, though, the pressures, the pain and the distractions got to him.