PHILADELPHIA — Eagles left guard Evan Mathis is not superstitious.

Unlike most NFL players, he has no pregame rituals because he found that it affected his focus. But he couldn’t be blamed if he showed up for Sunday’s game against Dallas with a rabbit’s foot or four-leaf clover.

Of the five offensive linemen who were projected to be the starters this season, Mathis is the only one who has not missed any time yet because of injury.

“It’s a little weird,” Mathis said Wednesday. “It’s getting to be kind of like a ‘Final Destination’ thing. I hope I don’t get hit by a bus.”

An offensive line that has been hit hard by injuries received another blow on Wednesday. The team announced that veteran right tackle Todd Herremans will miss the rest of the season with a dislocated cuboid bone and stretched tendon in his right ankle suffered during Monday’s 28-13 loss at New Orleans.

Because of the injuries, quarterback Michael Vick has been taking a beating this season. He has been sacked 27 times — fourth-most in the league. The Saints’ defense stormed into the Eagles’ backfield for seven sacks, the most Vick has ever suffered in a single game in his NFL career.

“It’s not the most fun thing in the world to get hit over and over and over again, but I just keep getting up,” Vick said Wednesday. “I have never played behind a line that’s had to shuffle so many guys in and out. But it’s part of the game. I’ve just got to believe in the guys in front of me. That’s part of my job as a quarterback. I’ve got to keep believing. Keep believing, stay optimistic.”

The offensive line was supposed to be one of the team’s strengths this season. Left tackle Jason Peters made his fifth Pro Bowl in 2011 and was regarded by some experts as the best offensive lineman in the NFL. Mathis also had a solid year in 2011, as did rookie center Jason Kelce and Herremans. Right guard Danny Watkins struggled at the outset of his rookie season but appeared to be making progress.

Then the unit began to fall apart.

Peters ruptured his right Achilles’ tendon during an offseason workout in March and hurt it again a month later. The Eagles are hoping he can return at some point this season, but he is probably at least a month away. Kelce, the anchor and leader of the line, tore two ligaments in his right knee in the second game of the season against Baltimore and is out for the year. Watkins has missed two straight games with chronic ankle soreness and did not practice on Wednesday. Herremans limped off the field against the Saints in the first quarter and was on crutches in the locker room after the game.

Various players have taken turns trying to plug the holes. Demetress Bell replaced Herremans at right tackle. Rookie Dennis Kelly, a sixth-round draft pick, played the last two games in Watkins’ spot, but had a rough outing against the Saints. Dallas Reynolds, who had spent the previous three seasons on the practice squad, replaced Kelce at center.

Part of the problem was that Kelly had never played guard before last week and Bell was making his NFL debut at right tackle.

“It was ‘Monday Night Football’ and I was probably a little over-amped and excited at first,” Kelly said Wednesday. “And when Todd went out, it made it hard because Demetress and I had never worked together before and didn’t know each other’s tendencies and things very well.”

More changes are coming for Sunday’s game against the Cowboys.

Bell played so badly against the Saints that he is being switched back to left tackle. King Dunlap will move from left tackle to replace Herremans at right tackle.

“Left tackle is all I know,” Bell said Wednesday. “It’s the only position I’ve ever played and where I’m more comfortable. I can’t explain it and I don’t want to make excuses, but playing right tackle (against the Saints) was very different.”

The offensive line has a very difficult challenge Sunday.

The Dallas defense is led by linebacker DeMarcus Ware, who leads the NFC with nine sacks.

“He’s one of the best pass rushers in the league,” Bell said. “He’s got quickness, strength, agility, he’s got it all. He can beat you at any moment.”

Contact David Weinberg: