Get your popcorn, the Washington Redskins’ quarterback competition begins at 4 p.m. today.

After five days of John Beck under center for all of the first-team (and most of the second-team) snaps, the fifth-year pro finally has a rival, as Rex Grossman is expected to take the practice field for the first time since signing another one-year deal Tuesday.

It isn’t quite Sonny vs. Billy, but offensive coordinator Kyle Shanahan says John vs. Rex will be “a battle” that he is “excited” to see.

The argument could be made that Beck has a head start because in the last five days, he has been able to shake off rust and make an impression with coaches. But on the other hand, Grossman is entering his third season in the system, and he started the last three games of the season, and should have a better handle on the playbook.

“It is going to be an advantage for Rex because he’s been in it a little bit longer,” Shanahan admits. “They both worked in it last year, but Rex is at a bit of an advantage because he has some actual game experience that he can work in it. But they’re both going to get a lot of action in the preseason, and it’s going to be a fun competition.”

When asked what Grossman has to do to win the job, Shanahan, who coached the ninth-year veteran in Houston in 2009, said: “He just has to play consistent. Rex at times can play as good as anyone, and then he can give them the ball too much. In the game against Dallas, he put together a half that not many quarterbacks all year played that well. And then in the Giants game, he had a few drives that we went down and then a couple third-down plays that we missed. Rex is very capable. He’s just got to know when to take that shot; he’s got to know when to take it down.”

Shanahan then praised Beck’s performance during the first week of camp.

“He’s done a good job. He’s possessed,” the offensive coordinator said. “He’s attacking this as hard as anyone could. He’s been working as hard as anyone could while he’s away from us and you can tell. He’s doing a really good job.”

Beck on Wednesday looked a little sharper than he had on Tuesday, when hampered by a sore throwing shoulder, he struggled with accuracy and velocity.

Mike Shanahan wouldn’t say how the snaps will be divided, but naturally, Beck’s snap count will go down. But the quarterback didn’t see that as a bad thing.

“The good thing is, I’ve been taking every rep as seriously as possible,” Beck said. “I’ve tried to make the most of every rep I’ve had. Will it limit reps? Definitely. … For me, I’m just trying to take it day-by-day, and I’ll worry about things I can control. With the reps, I’ll do the best with however many I get. There’s a little quote I remember from these past years that I’ve been a backup: ‘Don’t count your reps; make your reps count.’ I’m still going to approach it the same way and make every rep count.”