PHILADELPHIA (973espn.com) - Eagles tight end Zach Ertz suffered a rib injury in Sunday’s season-opening 29-10 win over the Cleveland Browns and is considered “week-to-week” moving forward, according to head coach Doug Pederson.

Pederson described the injury as a rib displacement in the collarbone area.

"Happened in the first quarter on their [Cleveland] sideline," the coach said. "He caught a pass. It wasn't the one-handed catch, but he caught a ball kind of left-to-right, and he turned up the sideline right on the boundary and went to protect himself and right on the sideline, lowered the shoulder and took a direct blow on his left shoulder."

Trainer Chris Peduzzi recognized something was wrong but the seriousness of the injury wasn't diagnosed until later.

"Right away when he came off after that series, Peduzzi came and said, ‘Hey, he's got a left shoulder strain,’" Pederson said. "We could tell that at the time. But as had game wore on, I didn't know obviously anything was more serious than that."

While the injury was described as a week-to-week one, it's extremely unlikely that Ertz will be available for the Week 2 Monday night affair in Chicago.

"(He's) probably going to have to be (medically) cleared," Pederson admitted. "It's a dangerous situation with a displaced bone. You are talking up around the neck and head area, so any type of blow again could do further damage to that. That's why it's a week-to-week deal to see how it heals and recovers."

Ertz finished the game against the Browns with six catches for 58 yards while playing in 78 percent of the offensive snaps.

Pederson also pegged starting cornerback Leodis McKelvin as week-to-week with a hamstring injury that forced him from Sunday’s game. Rookie Jalen Mills replaced McKelvin in the lineup and played well in 12 defensive snaps.

After trading Eric Rowe last week, the Eagles are all of a sudden very thin at the cornerback position and may have to promote undrafted rookie C.J. Smith from the practice squad.

"It's something we're going to address today with Howie [Eagles Executive Vice President of Football Operations Howie Roseman] and make a decision there," Pederson said. "We've got [CB] CJ Smith, as well, right now on the practice squad that could obviously come up. But we'll see where we're at. We'll talk to Jim [Eagles Defensive Coordinator Jim Schwartz] and look at it further. We've got a couple days this week, so it's good that we've got a little time."

Mills, however, would be expected to make his first NFL start if McKelvin is unable to play in Chicago.

"I thought he played well, coming in there and filling in for Leo," Pederson said when discussing Milla. "There's a good chance that he gets more work obviously this week. Very comfortable with what he has done so far through training camp. Again, he's another one of those young players that we have that will just get better with more reps."

In other injury news, Pederson said he expects tight end Trey Burton, who missed the Browns game with a calf injury suffered in practice last Friday, to be ready for the Week 2.

"It was a game-time decision yesterday with Trey." said Pederson. "And felt in his best interest and where we were as a team, [to] just rest him yesterday. And then again, he's got a couple good days here now to get ready. But I feel comfortable and confident that Trey will be ready to go."

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen

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