Offensive coordinator Kyle Shanahan, center, will help decide whether the Redskins start Rex Grossman, right, or John Beck on Sunday at Carolina. (John McDonnell/THE WASHINGTON POST)

To the surprise of no one inside or outside the Washington Redskins’ training facility, Mike Shanahan declined the opportunity Monday to name his starting quarterback for Sunday’s game at Carolina. That decision, the Redskins’ head coach said, will come Wednesday, when he will select either Rex Grossman, who was booed and benched in Sunday’s loss to Philadelphia, or John Beck, who hasn’t started a regular-season game since 2007.

But as the Redskins entered a week of uncertainty that, in some ways, seemed inevitable since training camp, when Grossman barely beat out Beck for the starter’s job, Shanahan reiterated what he has said since his team prepared for the season with a pair of journeymen.

“I got two guys that I believe in,” Shanahan said Monday. “I believe in Rex and I believe in John Beck. I’ve told you that from day one. Both guys, I’m hoping, are going to be here for a long time . . .

“Both these guys can play. I’ve been around quarterbacks in the National Football League for a long time, and I know these guys got what it takes, and whichever direction we go, that guy is going to [get] an opportunity to show us what he can do on game day.”

Grossman’s four interceptions in the first three quarters of the 20-13 loss to the Eagles brought Beck on for his first regular-season action as a Redskin. But it didn’t bring calls for a switch of the starting quarterback throughout the locker room. Though right tackle Jammal Brown said, “Beck went out there and looked real good,” veteran wide receiver Santana Moss, the Redskins’ offensive captain, adamantly argued that Grossman should retain the job.

“I think that he deserves to start,” Moss said. “[Philadelphia quarterback Michael] Vick threw four picks last week, came back and had a hell of a game. Tom Brady threw four picks [Sept. 25 against Buffalo]. . . . I just feel like you can’t just give up on a guy because he had a bad outing.”

Fellow wide receiver Jabar Gaffney, a college teammate of Grossman’s at Florida, added: “We’re behind him. We know what he can do. That was one game. He’ll get back to work.”

Neither quarterback was made available for comment Monday, but Shanahan said that kind of support is “exactly what you want. You want players supporting your quarterback.”

Still, the case against Grossman can be made through numbers. Through six weeks of the NFL season, he is tied with Carolina rookie Cam Newton for the league lead in interceptions with nine, even though Newton has played one more game. His interception rate of 5.5 percent is worst in the league; no one else’s is higher than 4.5 percent. Only one quarterback in the league has a lower passer rating than Grossman’s 66.5, and that player, Indianapolis’s Kerry Collins, hasn’t played since Week 3.

Beck, whose entire NFL body of work before Sunday’s 8-of-15, 117-yard performance consisted of five appearances for a hapless Miami team in his rookie season, described himself as rusty on Sunday.

“I’d say that’s a pretty good assessment,” Shanahan said Monday. “One of the high crosses, he’d like to have back; he had it a little low. One of the stick routes, he’d like to have back.”

Shanahan, in his 18th season as a head coach, has dealt with who’s-the-quarterback situations before. His most recent controversy came in 2006, the year he selected Jay Cutler in the first round of the draft. Jake Plummer was the incumbent starter, and he helped the Broncos to a 7-2 start. But in back-to-back losses to divisional opponents San Diego and Kansas City, Plummer threw two interceptions and one touchdown, and his passer rating dipped to 68.8. The Broncos started to lose hold of the AFC West, and Shanahan turned to the rookie.

“You have to make a decision: Is it just the quarterback?” Shanahan said. “Is it the offensive line? Is it your wide receivers? Is it decision-making? There’s a lot of things that go into it.”

Right now, a central theme must be the team’s inability to score. The Redskins have just nine offensive touchdowns in five games, the sixth-worst average in the league. The reasons for that, players and coaches said, are complex.

“As a total offense together, we have to give Grossman a better chance on some of those balls,” Moss said. “I feel like we can’t put it all on him. Yes, he threw the ball. Yes, it’s his decision. Yes, he’s going to take the blame. But as an offensive core, we’ve got to do a better job of making plays for him so he won’t have to do it all.”

That is true, regardless of who starts at quarterback. At the end of preseason, when Shanahan chose Grossman, he gathered his team before practice and told them his decision. Wednesday, there likely will be a similar scene at Redskins Park.

“What I think you have to do is, at least with your football team, is be honest,” Shanahan said. “You got to tell them what you’re thinking. You got to do what you think is in the best interest of your football team, based on the facts and the knowledge that you have at hand.”