The Eagles start a former tackle at guard and a former guard at center. Their starting right tackle has not started there since 2010, and their starting left tackle played right tackle for more than a half in the last game.

This is the Eagles' 2012 offensive line, a group beset by injuries that sidelined four of its previous starters and has allowed quarterback Michael Vick to be sacked 27 times this season.

When they play the Dallas Cowboys on Sunday, the Eagles likely will start Demetress Bell at left tackle, Evan Mathis at left guard, Dallas Reynolds at center, Dennis Kelly at right guard, and King Dunlap at right tackle. Only Mathis was supposed to start this season, and only Bell and Mathis are playing their natural side and position.

Tackles Todd Herremans (foot) and Jason Peters (Achilles tendon), guard Danny Watkins (ankle), and center Jason Kelce (knee) are sidelined by injuries.

The situation could create distress for offensive line coach Howard Mudd, but he's not viewing it that way. Mudd has hope of solving the problems because the linemen have been groomed to be versatile.

"Ever see Evita? There's a song in there, 'Don't Cry for Me . . .'," Mudd said Thursday. "Well, we've got some difficulties [with injuries], but the nice thing is we have some guys who move around.

"When Dennis was not [starting], he was playing right tackle, right guard, . . . left guard. The only thing he was not doing was hiking. So then he's ready to go. Dallas Reynolds had been a center some, but he has been a guard and a center. So let's go. I trust them."

Mudd said it's easier for a player to learn multiple positions at an early stage of his career. As an example, he said former Eagles right tackle Jon Runyan would not have been as adept at switching sides because right tackle was the only role he knew. But Kelly has worked at all spots this season, so there is confidence he can play guard even if he profiles as a right tackle.

Dunlap has played all spots except center, so he can move to the right side to replace Herremans.

Players on the Eagles' offensive line have said that there is not much difference between guard and tackle in Mudd's system, which requires an understanding of angles and footwork, and that the angles for a guard are similar to - not exactly like - those for a tackle. Mudd's goal is to form a dish-like shape for the pocket. A guard needs only to turn slightly. A tackle must turn more to create a "junction point," as Mudd terms it, to form the shape. But the fundamentals of the spots are the same.

"You change a few things. You set your angles just a little bit different. But all the technique is the same," rookie guard and tackle Nate Menkin said.

Mudd does not put a premium on a left tackle compared to a right tackle. When asked whether most teams have their best pass rusher at right end, he said that was not always the case.

For example, the Cowboys move DeMarcus Ware around, even though he is listed at right outside linebacker. Ware rushes 67.4 percent of the time from the right side and 22.9 percent from the left, so he might threaten both Bell and Dunlap. Mudd also mentioned former stars Charles Haley and Deacon Jones as great pass rushers who came from the left side.

During practice this week, Mudd has continued to preach fundamentals. Menkin, who is one of the inexperienced players on the line, said there's been a noticeable difference in the technical aspects of the performance of the Eagles linemen, especially the young linemen.

"They're getting better every day, both as a group and as a unit every day, and good things tend to happen," offensive coordinator Marty Mornhinweg said.

The Eagles need those improvements to happen quickly. The offensive line is the weakest spot on the team and hinders the entire offense. The personnel are not what the Eagles anticipated before the season, and it's up to Mudd to develop them into an able group.

Mudd, who has coached for nearly four decades, hasn't experienced the loss of four starters before. He acknowledged it's "a challenge," but said the problems can be corrected.

"We have no choice. We're fixing it the way we know how to fix it," Mudd said. "But I trust them. . . . I have a good feeling."

Inquirer staff writer Jeff McLane discusses the offensive strategy the Eagles may go to Sunday, when they face the Dallas Cowboys at Lincoln Financial Field.