FLORHAM PARK, N.J. (AP) — The New York Jets' secondary might be down a starter against the Atlanta Falcons.

Cornerback Buster Skrine has a concussion and his status is uncertain for the game Sunday at MetLife Stadium.

It is the third known concussion in just over two years for Skrine, who was injured last Sunday at Miami but finished the game.

"He came in Monday morning and they diagnosed him then," coach Todd Bowles said Wednesday.

Skrine has started all seven games this season opposite Morris Claiborne in the Jets' base defense, but is also the team's primary nickel back when it goes with a five-defensive back look. He had a rough performance against the Dolphins, having a role in allowing three touchdowns while also being called for three penalties.

Xavier Coleman, Skrine's backup at nickel back, was placed on injured reserve Wednesday with a shoulder injury. The Jets promoted cornerback Robert Nelson from the practice squad, but it's unclear who might fill Skrine's role in the nickel spot.

Nelson, Darryl Roberts and Juston Burris are all normally used on the outside in coverage.

"We have some gymnastics to work out," Bowles said of his secondary.

Skrine suffered a concussion against Washington on Oct. 18, 2015, and another against San Francisco on Dec. 11, 2016.

Bowles was uncertain when the latest concussion occurred, but Skrine collided with Miami receiver Leonte Carroo and his helmet popped off midway through the fourth quarter of New York's 31-28 loss. He remained in the game after the hit.

Bowles wouldn't attribute Skrine's bad day to possibly having played with a concussion.

"I don't know," the coach said. "I mean, I didn't know about it at the time. We just have to play better. I don't want to say that was the cause of it because I don't know when he got it."

In other injuries: Right tackle Brandon Shell (neck), defensive end Muhammad Wilkerson (shoulder/foot) and rookie tight end Jordan Leggett (knee) all sat out practice. Wide receiver Robby Anderson (ankle) was limited.

Quarterback Josh McCown was also listed on the team's injury report with a back ailment, but he practiced fully.

Shell injured his neck early against Miami and was replaced by Brent Qvale. Bowles said tests came back negative and Shell is day to day.

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