LAKE FOREST, Ill. -- Chicago Bears defensive end Lamarr Houston ruptured his right ACL while celebrating a sack of backup quarterback Jimmy Garoppolo during the fourth quarter of the club's 51-23 loss to the New England Patriots on Sunday, Bears general manager Phil Emery confirmed Monday.

Emery said Houston faces a rehabilitation of six to eight months.

The Bears signed Houston to a five-year, $35 million contract in March that included $14.9 million in guarantees, but the five-year veteran failed to register a sack until Sunday.

"Obviously, Lamarr had built up some frustration from not having a sack yet," Emery said. "We were very pleased with his play against the run and he led our team in hits on the quarterback, but he hadn't had a sack. Obviously, that's a big stat in the NFL. It's awfully big for a free agent coming in. He got his first sack, he let out all of his frustrations and ultimately paid a price for it.

"We're disappointed for him and in him. He knows he made an error. He's come into all of our offices and apologized for his error but ultimately the team paid a price and at the end of the day Lamarr paid a bigger price; he lost the season. So enough said."

The celebration and subsequent injury were reminiscent of an injury suffered by Detroit Lions linebacker Stephen Tulloch, who tore his ACL earlier in the season while celebrating.

Also, Emery said left guard Matt Slauson is out for the season with a torn right pectoral muscle. He faces a rehab of three to four months.

The Bears left open the possibility of sliding right tackle Jordan Mills inside to guard to replace Slauson. Mills (foot) was inactive in Week 8, but the injury is not believed to be serious.

"We're going to talk about [how to replace Slauson] today," Bears coach Marc Trestman said. "We've got a number of guys we can move into that position. We can go with Jordan moving into that position. We could go with Eben [Britton] moving into that position. We've got some young guys we're developing. We'll see how that goes along the way. But that will be the starting point."

Injured linebackers Lance Briggs (ribs) and Jon Bostic (back) are expected to return for the Green Bay Packers game on Nov. 9, following the bye week, according to Emery.