One by one, Rex Grossman’s teammates spotted the quarterback on the field during the Redskins’ afternoon walkthrough and sought him out for handshakes, high-fives and a couple of laughs. His arrival was hardly a surprise and catching up didn’t take too long. There was really only one unanswered question.

“What the hell took you so long?” wide receiver Anthony Armstrong asked, poking his head into Grossman’s meeting with reporters.

Grossman’s arrival at Redskins Park on Tuesday afternoon kicked off the one training camp story line that trumps all others. The battle for the starting quarterback job — John Beck vs. Rex Grossman — has formally begun.

Grossman, 30, signed a one-year contract with the Redskins on Tuesday, offering no explanation as to why negotiations dragged on for several days, but saying he’s eager to provide an answer to the biggest question on the team’s depth chart.

“This is all I can ask for: an offense I love, a bunch of players I think are really good,” he said. “I’m excited about this team, this offense and my opportunity.”

Grossman’s arrival might actually be welcome news for Beck. When the team opened camp last week, Beck was one of only two quarterbacks on the roster. The past few practices, he’s been splitting reps with a pair of undrafted rookies, but all the work has taken a toll on Beck’s arm. He’s thrown several balls that have been short or behind their intended targets. Some longer passes have wobbled their way to the receiver.

Redskins Coach Mike Shanahan said Beck might have been forced to carry too heavy a workload in the opening days of camp.

“You don’t want to overdo it,” Shanahan said “Even though John’s gotten a lot of reps, in the back of your mind you don’t want to overwork him. His arm was a little sore today, I could see it.”

Grossman and Kellen Clemens, a sixth-year veteran added last week, should be able to practice beginning Thursday, which gives them eight days to prepare for the first preseason game against Pittsburgh. Clemens has been observing practices and both quarterbacks were at Tuesday afternoon’s walkthrough.

Grossman has more experience in Shanahan’s offense than any other quarterback on the roster, so he should be able to step in Thursday without much problem.

“He’s been doing all the things mentally that a quarterback has to do in order to be prepared,” Shanahan said. “He knows the playbook and has a good feel for the system. Now he gets the chance to compete.”

Despite some of the attention showered on Beck during the offseason, coaches have stressed that the quarterback job is an open competition. Coaches are expected to split the reps between them, divide playing time in the four preseason games and withhold naming a starter until Week 1 nears.

“They all got a good opportunity,” said offensive coordinator Kyle Shanahan. “Whenever you don’t have a designated starter, you got a lot of competition.”

Even though he wasn’t under contract, Grossman attended the team’s player-organized workouts, along with Beck. Grossman said he also took home a Redskins playbook to study and spent the offseason watching tapes of the Redskins and the Houston Texans’ offenses.

Grossman originally signed with the Redskins as a free agent prior to the 2010 season. He’d played under Kyle Shanahan in 2009 as a backup to Matt Schaub in Houston. Washington already had Donovan McNabb and even Grossman didn’t foresee that he might be unseating the six-time Pro Bowler.

“When you bring in somebody like a Donovan McNabb, you don't expect this to happen,” he said.

Late in the year, McNabb was demoted to third string and Grossman started the Redskins’ final three games. He threw for more than 300 yards against both the Cowboys and the Giants, and totaled seven touchdowns and four interceptions.

“I want to be able to do the second half of the Cowboys game throughout 16 weeks and on through the playoffs as well,” Grossman said of a half in which he was 18-of-30 passing for 214 yards and three touchdowns. “That’s my challenge: to be consistently great.”

Beck has only three complete games under his belt — all from his rookie season in 2007. He didn’t top 180 yards in any of them, threw no touchdowns and had three interceptions. Playing for a terrible Miami team, he lost the starting job two passes into his fourth game. The Dolphins went on to finish 1-15 that season.

“He wasn’t bad in those games,” said Kyle Shanahan. “Really hasn’t shown that he can’t do it. He’s capable of doing everything. We’ll try to get him ready and see how he does in the preseason.”

Coaches have been complimentary of both passers in recent days. Even if some fans aren’t certain that confidence matches up with the quarterbacks’ credentials, both Beck and Grossman are self-assured. They know the job won’t be won on the podium in front of microphones and tape recorders. They have just one month to sell themselves to coaches.

“I’m going to go try to prove it with how I perform,” Grossman said, “not with anything else.”