The Washington Redskins got a major scare today when right guard Tre Johnson reinjured his right knee. Johnson and trainer Bubba Tyer said they are hopeful the injury isn't serious, but the Redskins were reminded just how precarious their offensive line situation is.

Johnson, whose 1998 season ended early because of an injury to his right knee, got his leg caught beneath another player while running a play during this morning's practice. He sat out the rest of practice but was able to walk off the field without help. Tyer called the injury a mild sprain.

"I think he's going to be fine," Tyer said.

Johnson, who wears a brace on the knee, said he hopes he can resume practicing on Monday. He wasn't scheduled to play in Saturday's scrimmage against the Pittsburgh Steelers, and Sunday is the players' day off.

"Someone rolled up on my leg," Johnson said. "I don't think it's too bad. It's just an everyday thing. I already had the next two days off, so hopefully I'll be okay."

It had been, until today, a trouble-free training camp for Johnson. He reported to camp in shape, and has done everything asked of him as he makes the transition from left to right guard. Redskins coaches have clashed with Johnson in the past about his approach to training camp and his willingness to practice with pain, but they have been delighted with what they've seen from Johnson during this camp.

"It's been a great camp," Johnson said. "I've been doing everything. Things happen. It gets your attention, but hopefully it won't be too much of a setback."

The Redskins can't afford major injuries to their offensive line. The unit surrendered a franchise-record 61 sacks last season, and protecting new quarterback Brad Johnson this season is a top priority.

Rookie Jon Jansen already is a fixture at right tackle, and former Pro Bowler Keith Sims appears well on his way to winning the starting job at left guard from Brad Badger. Sims has gotten all the work with the starting offense this week. Cory Raymer is set to start at center.

Left tackle remains a problem area, however. Redskins officials expect veteran free agent signee Andy Heck to win the job, but he's had a disappointing camp and Joe Patton continues to work with the starting unit. Another alternative could be to move one of the backup right tackles, Jamie Brown or Shar Pourdanesh.

Kickers Given Warning

Coach Norv Turner issued a shape-up-or-else message today to place kickers Cary Blanchard, Jeff Hall and Brett Conway after watching them struggle during this morning's practice. Turner said the season-opening kicker could come from outside the organization if none of them emerge in their three-way competition.

"Today it was a major concern," Turner said. "We're going to keep kicking these guys and come away with the best guy, and stay on top of every kicker in the league who might become available."

Asked whether he believes the Redskins' opening-day kicker is in the team's training camp, Turner said: "I think he could be. But he wasn't today." . . .

Turner said he doesn't plan to play any starters or players vying for starting jobs during Saturday's scrimmage. Casey Weldon is scheduled to get most of the snaps at quarterback, and fourth-stringer John Paci also could play.