The Washington Redskins will play in their fourth and final preseason game Thursday night, taking on the visiting Tampa Bay Buccaneers, but they still don’t know who will start for them at quarterback when the regular season begins.

John Beck and Rex Grossman will continue to try to one-up each other when they alternate against Tampy Bay (who will start the game also remains a mystery, by Coach Mike Shanahan’s design). They could duke it out all the way up until the eve of the Sept. 11 regular season opener against the New York Giants.

Both quarterbacks are obviously eager to learn the outcome of the competition, and teammates have said they too are curious about which passer Shanahan will anoint. But offensive coordinator Kyle Shanahan doesn’t believe the uncertainty is having a wearing affect on his players.

“The guys are not worried about the quarterbacks,” he said “I think guys are worried about their job and making the team themselves. If you have a player worried about a quarterback situation, I usually think that’s make believe. I think they’re worried about beating the guy in front of them. As long as that guy can call the plays and execute the offense, I think they’re going to go with who ever is in there.”

Both quarterbacks have avoided answering the question of whether the drawn-out competition is affecting them mentally. But given the way both have played (Grossman has completed 64.2 percent of his passes, with two touchdowns and an interception; Beck has completed 74.1 percent of his passes with a touchdown and an interception), Kyle Shanahan believes both have done a good job of dealing with the pressure.

“I think these guys knew going in that it was going to be a competition. I think this is the situation they’ve been preparing for,” Shanahan said. “I think both of them are strong enough people, mentally. I believe they are secure enough and expected this situation. I think both of them are doing a good job handling the pressure.”