Washington Redskins fullback Larry Bowie broke his left ankle in a freak accident during a rain-drenched practice yesterday at Redskin Park. He likely will spend five weeks in a cast, followed by perhaps five weeks of rehabilitation, leaving the Redskins without their best blocker in the backfield for at least the first half of the 1999 season.

The injury occurred on the Redskins' new artificial turf practice field, where the two-hour session had been moved after rain soaked the team's other fields. Bowie leaped in the air to avoid tripping over another player's legs, but landed hard on his left leg. Then another player rolled on his ankle.

Coach Norv Turner "said they looked at it on film and it was a pretty heavy hit," trainer Bubba Tyer said. "Someone was rolling toward him, and he jumped up to try to miss him, put all his weight on his leg, and somebody rolled into him. It was a substantial hit."

Bowie broke the same bone in the Redskins' Oct. 4 game against the Dallas Cowboys last season. It's unclear whether the bone snapped in the same spot, according to Tyer. Yesterday's fracture, however, is less severe than the one last year, which required the surgical insertion of a pin to set it.

Asked how difficult it would be for Bowie to return, Tyer said: "I can't answer that. I don't know. It's not as bad a break as last year, because you don't have to have surgery. But I can't answer that."

Unable to put weight on the ankle, the 6-foot, 242-pound back was helped off the field and driven away on an equipment cart. Bowie was sent to Commonwealth Orthopaedics in Loudoun County, where X-rays confirmed a nondisplaced fracture, which means both ends of the break remain in their proper place, with no deformity or dislocation.

"It's really disappointing for us, and it's really disappointing for him," Turner said. "It was a freak deal. When he came down, someone fell on his leg."

Bowie will be seen by Gordon Avery, the team's doctor, today and possibly have more X-rays. "It'll probably be about five weeks in a cast and several weeks after that of rehab," Tyer said. "It could be another five week of rehab."

Bowie, 26, started the preseason opener against New England, catching two passes for 21 yards. Against Buffalo last week, he played behind Larry Centers and caught a nine-yard pass. But Bowie's primary contribution in his three seasons with the Redskins has been as a burly blocker.

Fullback Mike Sellers had moved to tight end because of the logjam in the backfield and injuries to starter Stephen Alexander and backup Kevin Pesak. But Sellers could move back to fullback if the need arose.

Bowie is not the flashiest Redskin. But he is well-liked by teammates and highly valued by coaches for his blocking ability and work ethic. He had worked particularly hard to recover from the fractured fibula last year, showing up regularly at Redskin Park for therapy and workouts. He progressed nicely, Tyer said, but started experiencing pain in spring as he ran.

He was examined by specialists as well as team doctors, whose consensus was to let him continue working. He started slowly in training camp, but ran with more speed and ease as camp progressed.

Redskins Notes: Wide receiver Irving Fryar will play very little, if at all, Saturday against Pittsburgh, but Turner said he should be ready for the Sept. 12 season opener. . . .

Quarterback Brad Johnson took all of his reps in practice yesterday despite a swollen left knee. The swelling is a result of some roughness to the cartilage in his knee rather than the arthroscopic surgery he underwent in May, Tyer said. Because Saturday's game is on artificial turf, Turner likely won't use Johnson for much more than a quarter. But Johnson, who has played on turf his whole career, said yesterday he actually likes the surface because he feels he moves better on it. "It's not a big issue to me," Johnson said.