FOXBOROUGH, Mass. — The Broncos will have to play without their starting middle linebacker for awhile.

Nate Irving suffered a serious right knee injury in the second half of the Broncos’ loss to New England. He will have a magnetic resonance imaging test on Monday back in Denver, but there is fear Irving suffered some form of ligament damage.

“I don’t remember how it happened,” Irving said as he hobbled out of the Gillette Stadium visitor’s locker room on crutches. “Not a good break. Not a good day.”

Irving’s knee was in such severe pain that several members of the Broncos’ medical team had to help him get dressed.

Lamin Barrow, a rookie fifth-round draft pick from LSU, finished the game at middle linebacker during the rare plays when the Broncos’ employed their base defense. Steven Johnson could also start in Irving’s place next week at Oakland, although the third-year linebacker missed his second consecutive game Sunday because of an ankle injury.

“We’ll see how they play it this week,” said Barrow, who waited with Irving in the locker room after every other player had dressed and left for the busses. “Right now, I’m just praying for Nate. Hopefully, it’s not as bad as it looks right now.”