Dunlap, who has taken Bell's place at left tackle, was in Bell's shoes last August, although under different circumstances. Mudd had a carousel of linemen at right tackle through camp, and Dunlap briefly jumped in as a starter. But he lasted all of two preseason games.
"At first I was overthinking it," Dunlap said Saturday. "I think that's kind of what Demetress is doing - he's overthinking it. It's not as complicated as it seems. Going from setting vertical to straight forward is different footwork. But I was trying to make more of it."
Like Bell, Dunlap had used only the vertical step, a method in which an offensive lineman steps backward to give space before a defensive lineman makes his move. Mudd wants each of his players to be the aggressor and to get his hands on the defender before he attacks.
Dunlap said he figured out how to adjust by last year's third preseason game.
"It's actually a lot simpler than it seems," Dunlap said. "For me, it was taking smaller steps. It helped me stay wider and gave me greater balance. I don't know what [Bell's] thing is, but that's what did it for me."
Bell, signed April 4 - a week after Pro Bowler Jason Peters ruptured his Achilles tendon - played all of six plays in the preseason opener on Aug. 9 against the Steelers before the Eagles decided it was time to make the switch. Bell did not perform well. But it was just six snaps.
Obviously Mudd, coach Andy Reid, and offensive coordinator Marty Mornhinweg did not like what they had seen in practice despite the news conference bouquets that were being tossed in Bell's direction.
"It is a new system. It's totally new. It's totally new," Bell said. "But I can't use that as an excuse. I think I'm athletic enough to do what they've asked."
Behind the scenes, it's not as much technique as it is consistency that Eagles coaches have seen lacking in Bell's play. That could suggest that the team was using the demotion just to motivate the 28-year-old.
Ideally, Bell would start the season. As impressive as his five-year, $34.5 million contract sounded, only one year and $3.15 million is guaranteed. But that is still approximately $2 million more than Dunlap signed for in late March.
Reid, though, always made sure to include Dunlap whenever he was asked about his left tackle situation.
"They told me when I re-signed I was going to have a chance to compete for that spot," Dunlap said. "I guess it came sooner than later."
The Eagles are still calling it a competition, and it very well could be. Dunlap will start Monday at New England, and if he falters, Bell could get another chance. But if Dunlap acquits himself against the Patriots' 3-4 front, Reid and company won't be afraid to pull the plug on Bell.
Four of the Eagles' first five regular-season opponents employ an odd-man front. The Eagles can't bide time waiting for Bell as they did with top pick Danny Watkins last year. There was a first-round investment with Watkins, and the right guard was much more raw.
Bell has been in the NFL for four years and has 30 career starts - 25 more than Dunlap - playing in the vertical set. On Thursday, former Eagles great Tra Thomas, a master of the vertical step, retired. Current Eagles right tackle Todd Herremans was asked if Thomas would have been able to make the adjustment to Mudd's style mid-career, and he said no.
"You're always aggressive. You're never passive. Run block or pass block - you're aggressive," Bell said. "If you're going out there full speed . . . the end could be 5 yards by you with his first step."
There's a certain comfort the Eagles have with Dunlap. Only seven players - Mike Patterson, Herremans, Trent Cole, Jason Avant, Jon Dorenbos, Brent Celek, and Akeem Jordan - have been here longer than Dunlap, who was taken in the seventh round of the 2008 draft.
He's never been the greatest practice player because of his size and fatigue.
"Howard used to get on me for that," Dunlap said. "When you get tired you do what your body remembers, and for me that was setting vertical."
But once he started taking smaller steps Dunlap said he was able to get his body lower. His height has always been one of his primary issues. His brittleness has been another. But Dunlap tends to get top-heavy, making it easier for ends to either bull rush or zoom around him.
If he does earn the starting spot it remains to be seen how effective he can be as a run blocker, especially one who can run in space as Peters did so masterfully last year.
"Jason is a rare commodity at that size and being able to move like that," Dunlap said. "I feel like I can be just as effective downfield. It's a little harder for me because I'm taller."
Contact Jeff McLane at 215-854-4745 or firstname.lastname@example.org, or follow on Twitter @Jeff_McLane.