Mike Shanahan now says health -- not knowledge -- was the main reason why he pulled Donovan McNabb with the game on the line.

A day after saying he benched Donovan McNabb with the game on the line in Detroit because he still didn’t know the two-minute offense eight weeks into the season, Mike Shanahan is back-pedaling, bobbing and weaving.

Shanahan on this day says that his starting quarterback wasn’t in good enough cardiovascular shape to handle running the two-minute offense, and so going with Rex Grossman was the right move. The coach also said that the Redskins hadn’t practiced the two minute offense in more than a month.

“The last time we ran the two-minute offense was against the Rams game. We ran it about 10, 11 plays, and I thought Donovan did an excellent job,” Shanahan said. “From that point, we have not practiced the two-minute attack. Donovan has been hampered by some hamstring injuries, quad injuries, some contusions down there. … So, when you’re dealing with a two-minute offense and you don’t have any timeouts, and you haven’t run it in five weeks, and you’re calling, some times two plays as you’re hustling to the line of scrimmage and you’re calling plays that you haven’t called in a two-minute attack, and you’re actually working cardiovascular endurance at the same time, working on the clock, it’s really hard to do that when you haven’t practiced it, and you haven’t put yourself out in any strenuous activities, it might be in the best interest to go in a different direction. And that’s why I did it.”

Interesting enough, McNabb on Sunday was Washington’s leading rusher, averaging 11.3 yards on four carries -- including a 36-yard yard run, which was his longest run since 2007.

Perhaps sprinting 36 yards as well as all the dancing McNabb did in the backfield to avoid one blitzer after another throughout the Lions game, isn’t strenuous in Shanahan’s eyes.

But anyway . . ..

Shanahan also now has changed his story on when he made the decision to bench McNabb. Sunday after the loss, Shanahan was asked how long he thought about pulling McNabb before making the decision and replied, “It was a gut move. You kinda go with your gut-feel.”

The coach now says that he made the decision before the game even began. Shanahan said he met with McNabb on Tuesday (five days before Washington faced Detroit) and told the quarterback that the team’s trainers had concerns about McNabb’s hamstring injuries to both legs, as well as some contusions, and that the coach suggested the quarterback sit out the Lions game altogether and save himself for the second half of the season.

Shanahan said McNabb assured him that he wouldn’t further injure himself, but said he still made up in his mind that if it came to a two-minute situation with no timeouts, Rex Grossman would be his guy instead of McNabb -- the quarterback that has 15 fourth-quarter comebacks and 23 game-winning drives.

But Shanahan said that put in the same situation, he would go with Grossman all over again.

“I think I just tried to explain to you, the cardiovascular endurance, it takes to run a two-minute 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’ve been in there. The way it turned out, we weren’t counting on the pressure inside and the fumble and those type of things. That’s why we talked about it earlier in the week. The bigger question was, was Donovan going to play.”

There are multiple problems with that statement, there, however.

Detroit rookie defensive tackle Ndamukong Suh had two sacks, two tackles for a loss and two hits on the quarterback. The Lions -- like every other Redskins opponent -- were making a living off of pressure up the middle. Yet, Shanahan wasn’t “counting on pressure inside.”

Secondly, Shanahan said “that’s why we talked about it earlier in the week.” The coach admitted that he didn’t talk with McNabb about pulling him with the game on the line at any point before McNabb was told Grossman was going in. “No, I did not talk to Donovan. Not at all,” the coach said.

Not exactly treatment you would expect of a franchise quarterback.

When asked if he had informed Grossman before the game, Shanahan said, “I’m not going to go into my discussions with people, but I did talk to some people. But I’m not going to go into who I talked to because once I go down that road, I open up Pandora’s box.”

Shanahan said it didn’t matter that like McNabb, Grossman hadn’t practiced the two-minute offense this season. But later he said that Grossman had run the Indianapolis Colts’ two-minute offense for the scout team and “did quite well at it.”

Shanahan said he remains confident in McNabb and that he wants to re-sign the quarterback in the offseason, but he did express displeasure with the offense as a whole.

“I understand what you go through when you do this and I don’t mind explaining why I made this decision,” Shanahan said. “But in saying that, I’m not happy with where we’re at offensively. As I told Donovan, I said, ‘Hey, you’ve got a ways to go, our offensive line has a ways to go, our receivers; collectively, our coaching staff -- we’re not happy with where we’re at.' But that’s not the reason why we went that direction in the two-minute offense. But we’re not happy. We’ve got a ways to go, and we’re all accountable, starting with me. And hopefully we can get there.”

Donovan McNabb didn’t speak to reporters today, but yesterday made no mention of poor conditioning or ailing hamstrings. Instead, McNabb acknowledged that Shanahan didn’t believe he was fluent enough in the two-minute offense. The quarterback professionally declared that stance to be inaccurate, and said he was fully capable of leading the Redskins down the field for a game-winning drive.

It’s not yet known if he will speak to the media on Tuesday, which is the last day that players will be at Redskins Park this week since the team has a bye this coming Sunday.