"You can't constantly turn the football over," Shanahan said. "And if you do, you're going to lose your opportunity to lead the football team."
Washington's QB carousel
» 1993: Mark Rypien (10), Rich Gannon (4), Cary Conklin (2)
» 1994: Heath Shuler (8), John Friesz (4), Gus Frerotte (4)
» 1995: Frerotte (11), Shuler (5)
» 1996: Frerotte (16)
» 1997: Frerotte (13), Jeff Hostetler (3)
» 1998: Trent Green (14), Frerotte (2)
» 1999: Brad Johnson (16)
» 2000: Johnson (11), Jeff George (5)
» 2001: Tony Banks (14), George (2)
» 2002: Shane Matthews (7), Patrick Ramsey (5), Danny Wuerffel (4)
» 2003: Ramsey (11), Tim Hasselbeck (5)
» 2004: Mark Brunell (9), Ramsey (7)
» 2005: Brunell (15), Ramsey (1)
» 2006: Brunell (9), Jason Campbell (7)
» 2007: Campbell (13), Todd Collins (3)
» 2008: Campbell (16)
» 2009: Campbell (16)
» 2010: Donovan McNabb (13), Rex Grossman (3)
» 2011: Grossman (5), John Beck (?)
"There's been a lot of hard work that's gone into this," Beck said. "You never know when your opportunity's going to come, and you've always got to stay ready. I've tried to do that."
Beck and Grossman took turns at the burgundy podium expressing their respective excitement and disappointment, reversing their roles from six weeks ago when Grossman won the job at the end of training camp.
"Things change," Beck said, "in the blink of an eye."
Shanahan called the quarterbacks into his office Tuesday to inform them of the switch.
"I was frustrated," Grossman said. "Not completely surprised, but I'm disappointed that I wasn't able to come back off that game."
Grossman's quarterback rating is 66.5, ranking 32nd of 33 quarterbacks in the league. He's ahead of Indianapolis' Kerry Collins, who hasn't played since Week 3.
Yet Grossman on Wednesday repeatedly defended his body of work leading up to the Philadelphia game.
"The frustrating part about it is I do think that they were good performances. The frustrating part is they should have been great," he said. "I had an opportunity to make it clear as day, and it wasn't. For the first four games, I played well. And I could show you to prove it, but it doesn't matter."
Grossman admitted he had an "unacceptable performance" against the Eagles and that he perhaps needs to change his mind-set when it comes to turnovers.
"The only thing I could do that could maybe encompass all turnovers -- just have a little more conservative approach to the fact that, hey, turnovers are bad, but they're emotional mistakes that create emotion in the stands, create an odd emotion everywhere," Grossman said.
"Ultimately," he said, "I'm responsible for the ball."
"I have a lot of confidence in John Beck because he does have that mobility, that strong arm," Shanahan said. "I'm not going to be putting him in the Hall of Fame yet, but I really do believe he's got a lot of talent."
Beck said he's improved since training camp, having learned more about the offense as the No. 2, making up for study time lost during the NFL lockout. He completed 8 of 15 passes for 117 yards in relief against the Eagles and scored on a 2-yard run.
That gave him a modest QB rating of 79.0 -- much better than in any of his five games with the Dolphins. He went 0-4 as a starter in 2007 and made one relief appearance for a bad team.
Copyright 2011 by The Associated Press