Penn State’s elite defense will be without a critical piece for the remainder of 2015.

The team announced that senior cornerback Jordan Lucas will be out the rest of the season with a right arm injury. The news also meant that Lucas’ career with the Lions came to an end on Saturday against Northwestern.

The PSU captain had dealt with a shoulder injury throughout the first half of the season, and appeared to have aggravated it on Saturday in the first half. He spent the entire second half in street clothes with his arm in a sling, though it wasn’t determined if it was a shoulder or an arm injury.

A two-time All-B1G honorable mention selection, Lucas had a streak of 27 straight games played before he was sidelined for the Sept. 26 game against San Diego State.

After a relatively clean injury history in his first three seasons, Lucas’ injury-shortened senior year saw him produce 56 tackles, which was good for fourth on the team. He also recorded 2.5 tackles for loss, three pass breakups, three passes defended and one forced fumble.

It’s another crushing blow for a defense that might be without NCAA sacks leader Carl Nassib, who exited in the fourth quarter with an apparent right arm injury. His future status has yet to be determined.

The Lions will be on a bye before ending the season with showdowns against Michigan and Michigan State.