ASHBURN, Va. -- Mike Shanahan changed his story in a hurry. The new explanation: Donovan McNabb was benched more because of his body, not his brain.
Less than 24 hours after declaring he yanked McNabb because of a "gut feel" relating to the quarterback's less-than-full competence in the offense, the Washington Redskins coach instead insisted Monday it was a pre-planned move that had more to do with "cardiovascular endurance" issues.
McNabb, because of nagging hamstring and groin injuries, wasn't in good enough shape to run a two-minute offense with no timeouts -- according to Shanahan.
"The cardiovascular endurance that it takes to run a two-minute, going all the way down with no timeouts, calling plays, it's just not easy." Shanahan said. "If I thought it was the best situation to do, then Donovan would have run the two-minute offense."
Somewhere in between the range of explanations is the cold fact: McNabb, who turns 34 this month, is not having a very good season.
The change of message by a coach with two Super Bowl titles made for a baffling day at Redskins Park, nearly eclipsing the stunning decision to sit McNabb in the first place.
With the Redskins trailing the Detroit Lions by six with 1:50 to play, Shanahan pulled McNabb in favor of Rex Grossman. It didn't work. The backup's first snap of the season turned into a touchdown for the other team, with Grossman fumbling the ball on a blindside sack and Ndamukong Suh returning it for the score.
Detroit won 37-25, leaving the Redskins (4-4) at .500 and still competitive in the NFC East as they enter their bye week -- assuming they can figure out what's happening between coach and quarterback.
After the game, Shanahan justified the move by citing the complexities of the two-minute offense. The game speeds up. Multiple plays have to be called at the line of scrimmage. It all has "to come automatically," the coach said. Grossman spent last season in this same offense under offensive coordinator Kyle Shanahan -- both were with the Houston Texans -- although Grossman was a rarely used backup who didn't run the two-minute offense in a regular season game.
Teammates could hardly believe it.
"For him to be pulled like that, it's definitely a shocker to a lot of us," cornerback DeAngelo Hall said. "It does raise the interesting point: After the season, will he be here or not?"
If McNabb hasn't grasped the offense enough to run a two-minute drill after seven months of study, there seemed to be only three possible conclusions: The offense is too complex, the coaches have done a poor job teaching it, or McNabb is a poor student.
Or a combination of the three. One of the knocks on McNabb in his 11 years with the Philadelphia Eagles was his struggles in the two-minute offense -- which came to light most embarrassingly when he took his time leading a drive late in the Super Bowl with his team trailing and the clock ticking away.
But one should always expect the unexpected with the Redskins. Shanahan came up with a fourth explanation: cardio.
Shanahan said McNabb, who has two tight hamstrings, a sore groin and a bruised shin, hasn't been able to practice the two-minute drill for five weeks. The coach said he even called the quarterback into the office last week and discussed the possibility of McNabb sitting out the game.
"I can see you're not setting your feet like you normally do when you're throwing the ball," Shanahan said he told McNabb.
It was decided that McNabb would play, but Shanahan said he decided before kickoff that he would pull his starter if there were a two-minute situation with no timeouts. The coach said he didn't inform McNabb of this decision because he said he didn't want to put the thought into McNabb's mind.
Asked why he didn't explain all this after the game on Sunday, Shanahan said he "didn't really want to go into a lot of detail" in the disappointment following a loss. Yet Shanahan did go into much detail in his postgame explanation, talking at length about the intricacies of running a two-minute offense.
Whatever the explanation, the elephant in the room is that McNabb is on pace for his worst season since his rookie year, when he only started six games. He has a 76.0 rating with only seven touchdown passes, and his eight interceptions have caused him to lose his prized spot as the NFL's career leader in interception percentage.
McNabb did not speak to reporters Monday, but on Sunday he handled his benching without making so much as a ripple. He said he would have liked to finish the game, but the coach makes the decision.
He did not mention his injuries or his fitness. His slow pace in mastering the new offense has been one of the developing stories since the start of training camp, and he said he expected to be farther along.
"I thought we would get things rolling by now," McNabb said. "When you spend 11 years doing anything, then you go to something new, there's a big change. But that's the past. My comfort level in this offense is good, and we just have to make sure we can be consistent in execution."
The Redskins gave up two draft picks for McNabb, whose contract expires at the end of the year. Those draft picks would appear to be a waste if McNabb isn't signed to a new deal, but contract talks haven't made much progress. Shanahan called McNabb "a franchise quarterback" and said the "lines of communication are open" with McNabb's agent and that McNabb will still be the starter in the Monday night game against the Eagles following the bye.
Even so, the offense remains a mess. Of Washington's 25 points against Detroit, 22 were directly attributable to good punt and kickoff returns by Brandon Banks.
"I'm not happy where we're at offensively," Shanahan said. "I told Donovan, 'You've got a ways to go.' Our offensive line has a ways to go, our receivers, our coaching staff, we're not happy where we're at."
Asked if the Redskins were interested in WR Randy Moss, Shanahan joked: "He's in our facility right now." Seriously, the coach said: "We'll look at Randy and make a decision if he gives us a better chance to help our football team win." ... Shanahan said an MRI on RB Ryan Torain's left hamstring showed no tear.