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.