Eagles starting left tackle Jordan Mailata missed practice Friday after suffering a knee sprain the day before, leaving his status going into Monday night’s game against the Dallas Cowboys in question.

The Eagles announced the injury Friday. Mailata wasn’t on the injury report after Thursday’s session because he didn’t tell the team about the discomfort in his knee right away, according to a team spokesperson. He was rolled on toward the end of practice Thursday and the Eagles are still evaluating the severity of the injury.

In Mailata’s absence, Andre Dillard was first up at left tackle during the portion of Friday’s practice open to the media. Mailata won the starting left tackle job over Dillard during training camp and earned a four-year, $64 million contract extension the day before the season opener.

Mailata has looked the part as the team’s starting left tackle so far this season. According to ESPN’s run-block win rate metric, the Australia native has been one of the best tackles in the league on running plays. He has also allowed just two pressures, according to Pro Football Focus, and was ranked as the website’s fourth-best offensive lineman going into Week 3.

Last Sunday, he was often matched up against 49ers defensive end Nick Bosa, one of the best edge rushers in the league.

“I thought he had a heck of a game,” Eagles offensive coordinator Shane Steichen said Wednesday. “Obviously, to be one-on-one with Bosa over there and do what he did against him was very impressive.”

The Eagles, who fielded 14 starting offensive line combinations in 16 games last season, already had one significant injury to deal with up front going into Texas. Starting right guard Brandon Brooks went on injured reserve earlier this week with a pectoral sprain suffered Sunday against San Francisco, and Landon Dickerson is set to take his place. The second-round rookie out of Alabama came in for Brooks and had an up-and-down afternoon.

If Mailata isn’t able to go, Dillard will likely make his fifth career start — the previous four came during his rookie season. Dillard struggled at times as a rookie in 2019, particularly when he was asked to fill in on the right side for a game against Seattle. Going into the game, he compared switching from left to right tackle to writing an essay with your opposite hand.

The 2019 first-round pick out of Washington State was expected to be the team’s starting left tackle the following season, but he had difficulty in pass protection during training camp and eventually suffered a season-ending biceps injury before the season began. This summer, he was beaten out by Mailata.

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Dillard struggled during one-on-one pass-rush drills at times and missed a little over a week with a knee injury midway through camp.

When asked how Dillard handled losing the starting competition, offensive line coach Jeff Stoutland said he was happy with Dillard’s training-camp performance for the most part but acknowledged the injury slowed his progress.

“He was doing well, I really mean that,” Stoutland said during a news conference last week. “I was very happy with some of the things that he was doing and then he got hurt and it became like, ‘Oh, man. Here we go again.’”