EAST RUTHERFORD, N.J. -- Justin Tuck finds a lot of things that happen in the NFL amusing.
But the New York Giants defensive end laughed out loud as if he were at a Chris Rock performance when he heard Mike Shanahan's explanations for why he pulled Donovan McNabb near the end of a game against the Detroit Lions earlier this season.
Shanahan said McNabb wasn't as proficient at running the two-minute offense as Rex Grossman is, before later clarifying that it was really because of McNabb's "cardiovascular endurance."
"I actually laughed," Tuck said.
"It was ridiculous," linebacker Michael Boley said.
"He passed his conditioning test in the beginning of the year, and [Albert] Haynesworth didn't," linebacker Keith Bulluck said, pointing out Washington's other major drama this season. "So it's like, which is it?"
While his own coach has doubts about him, McNabb will find nothing but respect in the Giants' locker room. They know firsthand how good McNabb can be.
McNabb has beaten the Giants four straight times, including a 23-11 playoff victory during the 2008 season. And now, McNabb stands in the Giants' way again, as they will play No. 5 twice in the span of a month starting Sunday.
McNabb no longer has Eagles game-breakers such as DeSean Jackson and LeSean McCoy on his side, and is working with a less-talented bunch in Washington. But he knows how to beat the Giants. So even though the Giants (7-4) have taken seven of their past eight meetings with the Redskins, they are not taking Washington lightly. If they want to win the NFC East, they will have to beat McNabb twice, along with beating his old Philadelphia team.
"It is going to be tough because he always plays well against us," Tuck said. "I've only had one game where I felt very confident in how we played as a defense against him."
Tuck said that was when the Giants sacked McNabb 12 times in a 16-3 victory during the 2007 season. McNabb is 11-7 overall, including playoff games, against the Giants in his career.
He holds a 10-6 regular-season mark against the Giants, and has found ways to beat them with his right arm and feet in a number of meaningful games.
Last season, he swept the Giants as the Eagles scored a combined 85 points in the two victories. McNabb threw five touchdown passes -- two of them 54 yards and 60 yards long, to Jackson.
"He's got it all," safety Deon Grant said. "All these things, how they call [Michael] Vick 'Superman' … [McNabb] has been doing it for years. He might not be as fast as Vick is, but he still has the powerful arm and can still get the feet to create situations when they aren't there."
The Eagles shocked the NFL world and the Giants when they dealt McNabb within the NFC East to the Redskins on Easter Sunday.
But the McNabb era in D.C. hasn't gone smoothly. There was the late-game benching at the end of October against Detroit in favor of Grossman -- who was with offensive coordinator Kyle Shanahan last season in Houston -- which still has some Giants stunned.
"I mean, if a guy has been your quarterback for that deep into the season, there is no way that you say that he can't run the two-minute offense," Boley said. "I think that was personal."
McNabb has thrown for more than one touchdown in a game only once this season and has been intercepted in nine straight games.
McNabb in burgundy and gold has not been as good as the one who wore green for 11 seasons.
"I honestly don't believe McNabb is truly healthy," Tuck said of the Redskins quarterback, who has dealt with a hamstring injury this season. "They have been in close games. They have had a lot of issues down there, too -- they are not completely healthy, issues along the O-line. It is a new system. As good as McNabb is, you are going to have some growing pains with a new coach in a new system."
And the Giants hope McNabb's continuing adjustments to a new team and new coach will play into their hands.
"Even though he's grasped the system, it's not the one like he was comfortable with in Philly," defensive coordinator Perry Fewell said. "I still see the savvy veteran quarterback that has a strong arm, and he's able to break you down. I see nothing different from Donovan himself except it's not the offense that he's been comfortable with for a number of years."
Fewell said some of McNabb's 13 interceptions have been a product of his receivers not being in the right spot at times, along with some bad throws.
"When he was in Philly, he knew where everyone was going to be and he was the general of that offense," Fewell said. "It's not like he's not the general of the [Washington] offense, but he doesn't know where everyone is deployed and where everybody is. He has made some mistakes as far as that is concerned from what I can see on tape."
The Giants don't need to watch a ton of film to know what McNabb is capable of. They've seen what he can do too many times in person.
And that is why they found Shanahan yanking McNabb earlier this season so laughable.
They just hope that by the time Sunday's game is over, they won't be seeing McNabb flashing that trademark smile of his, as he has the past four times he has faced the Giants.
"A lot of people don't give him enough credit," Grant said. "You look at what he did in Philly; those guys went to the NFC Championship Game [five] times. And they went to the Super Bowl. Whatever he is doing is working. We just have to make sure it doesn't work this week."