Holes to fill all over Eagles' O-line

David Molk was asked how many times he's played at guard, and he let out a big belly laugh.

Not many.

"By handful," Molk said, "I mean literally a handful."

The Eagles center had played only 15 snaps at his natural position in his entire NFL career. But after last season, when all five offensive linemen started all 17 games, the Eagles were down to their last active blocker on Sunday, and Molk was pressed into duty.

He played left guard, and over the course of 58 snaps - from late in the second quarter to the end of the game - the Eagles turned a 17-point deficit into a 34-17 victory over the Jacksonville Jaguars with Molk playing out of position.

He wasn't the only one. Andrew Gardner entered a series earlier, when left guard Evan Mathis vacated with a gruesome-looking knee injury. But when right tackle Allen Barbre hobbled off with a sprained ankle, Gardner jumped outside and Molk took his spot. Gardner had only played at left tackle in the preseason.

There were some shaky moments early on. The starting line wasn't consistent before the injuries either. But the unit settled down - as did the entire offense - and Nick Foles had more time in the pocket, and LeSean McCoy and Darren Sproles had a few more holes to dart through.

"I thought they did a good job," Eagles coach Chip Kelly said. "That is a fear when you have a 46-man roster. I think everybody has two people. We had two offensive linemen up - Molk and Gardner. When Allen went down and Evan went down, obviously you've got to play with those guys."

They may have to play with them - or at least another combination of backups - for longer if Mathis and Barbre are out for an extended period. The Eagles were already down starting right tackle Lane Johnson, who is serving a four-game suspension. And top backup Matt Tobin was out with a high-ankle sprain that is expected to sideline him for at least another week.

The early diagnosis on Mathis, according to sources close to the situation, was that he suffered an injury to the medial collateral ligament in his left knee, not the anterior cruciate ligament that many of his teammates initially feared.

"I just heard him start screaming, and I look back and he's on the ground," left tackle Jason Peters said. "And I was like, 'That must be bad if he's laying on the ground like that.' "

Center Jason Kelce, who tore his ACL in the second game of the 2012 season, said he thought the same thing. But Mathis isn't out of the woods. He'll have advanced testing on Monday morning that will determine the severity of the injury. Barbre said that he had to undergo further tests before a final diagnosis, too.

If both are out next week, Gardner and Dennis Kelly, who didn't dress, will be the likely replacements. As impressive as Molk's performance was, considering the circumstances, he has really only ever played center.

He said he took some snaps at guard for the Chargers last year. They released him before the season, and the Michigan product spent all of last year out of football. But the Eagles signed him in January, and he took the backup center spot after Julian Vandervelde underwent back surgery and was eventually cut.

Molk would have won the job anyway. But the Eagles need their game-day backup center to be able to swing and also play guard. Kelly said Molk took some practice repetitions there this week, but it was obviously limited.

"Everything's different," Molk said about playing guard as opposed to center. "Your leverage is different. Your angles are different. Where you place your hands is different. How you assess pass rush is totally different, where at center it's literally right in your face."

Molk said he learned that firsthand when a defensive tackle zoomed past him on his first play. Gardner, who was also an offseason free-agent acquisition, was beat inside on one of his early snaps at guard. But they didn't panic, they said, partly because they had played so much and so well in the preseason.

O-line depth was one of the primary concerns heading into camp. Peters, Mathis, Kelce, Johnson, and Todd Herremans started every game last year. But the second unit was one of the pleasant surprises of the preseason. The Eagles' O-line luck ran out starting with Johnson's suspension, but as unlucky as they were Sunday, they prepared for emergency.

"That's the way it goes sometimes," Kelce said. "Hopefully, we won't have to deal with too much more of this the rest of the season. And hopefully, the guys that are hurt can get back quick. It's fortunate that we have much better depth this year."

Molk said he wasn't ready to look past this game yet.

"I'm going to go home, take a deep breath," Molk said, "and try and figure out what the heck just happened."

They won.

@Jeff_McLane