Stephen Alexander, the Washington Redskins' starting tight end and one of the key components of their offense, suffered a sprained medial collateral ligament in his right knee early in last night's 20-19 preseason triumph over the Buffalo Bills. The injury is scheduled to be reevaluated today, and trainer Bubba Tyer said Alexander could be sidelined for two weeks.

On a night when Coach Norv Turner said he's leaning toward making Stephen Davis the team's starting running back, the Redskins were reminded just what a thin line they're walking. They don't have a dominant running back or wide receiver, and they can't afford to lose any of the playmakers they do have.

Alexander was hurt when running back Skip Hicks and a Bills defender fell on his leg on a first-quarter rushing play. Alexander returned for one more play but limped off the field and spent the remainder of the game on the sideline with an ice pack strapped to his knee.

Alexander said he probably would have continued to play in a regular season game, and added: "I stayed out just to make sure. We weren't going to take any chances this early."

Alexander's backup, Kevin Pesak, was helped off the field in the fourth quarter after spraining his left ankle. Pesak probably will be sidelined for two to three weeks, Tyer said.

The Redskins have two preseason games remaining, then open the regular season on Sept. 12 against the Dallas Cowboys at Redskins Stadium. The starting offense struggled last night, and the Redskins don't want to postpone the getting-to-know-you period for Alexander and quarterback Brad Johnson until the regular season.

Alexander could end up as one of Johnson's favorite targets. The offensive line couldn't keep Buffalo's pass rushers away from Johnson last night, an ominous sign for a club whose quarterbacks were sacked a franchise-record 61 times last season. Short passes to Alexander and running backs Larry Centers and Brian Mitchell might be Johnson's best weapon -- and his last resort.

Alexander split time with Jamie Asher last season as a rookie. He was bothered by a shoulder injury, but still had 37 catches for 383 yards and four touchdowns and demonstrated that he has the speed to be a downfield receiving threat.

The Redskins need all of those they can get. Johnson again had trouble last night getting the ball to starting wide receivers Michael Westbrook and Albert Connell. Irving Fryar, the seventh-leading receiver in NFL history who came out of retirement to sign with the Redskins this week, was on the sideline but wasn't in uniform. He likely will enter the mix in next Saturday's preseason game at Pittsburgh.

"We have a lot of work to do," Turner said.

The spotlight last night was on offensive tackle Andy Heck and Hicks. Heck started at left tackle after being moved ahead of Joe Patton on the depth chart this week. He had a difficult assignment, going against defensive end Bruce Smith, and got mixed results, including getting beaten badly on a play in the final moments of the first half when he was called for holding.

But the starting job almost certainly is his, for Patton may be on his way to being cut. He didn't play until the late stages of last night's game, after Kipp Vickers had worked with the second team.

Heck had a better night than Hicks, who may be on the verge of losing his battle for the starting tailback job to Davis. Hicks started last night but Turner showed little patience, going to Davis late in the first quarter. In the first half, with the starters still in the game, Hicks rushed for only six yards on five carries, and Davis had 35 yards on eight rushes.

Turner reiterated that the Redskins probably won't settle on a starting tailback until just before the regular season.

"I don't think it will be settled for a couple weeks," Turner said. "I know this: We'll need both of them during the regular season. One guy may have the edge, but we're not going to close the door on the other."

Still, Turner and his assistants appear to be growing increasingly impatient with Hicks's reluctance to grind out the tough yards between the tackles. Hicks bounces plays to the outside and attempts to turn nothing into something, but that approach doesn't always work. Davis's no-frills, straightforward style may win him a starting job, with Hicks filling in occasionally as a change-of-pace runner capable of providing a big play here and there.

"I was looking for too much," Hicks said late last night. "I was trying to hit the home run every time. A couple times, I missed a pretty good hole. I've got to look at what I did and try to get better next week."