Vikings left tackle Christian Darrisaw, one of the NFL's best blindside blockers, will require season-ending knee surgery, a league source confirmed.

Just before halftime of the Vikings' 30-20 loss on Thursday night, Darrisaw was hit from behind by a Rams defender tackling running back Aaron Jones. He fell to the ground, clutching his left knee. Teammates circled him, fearing the worst. Those fears came true Friday when testing confirmed Darrisaw's season is over after seven games. The nature of Darrisaw's injury is unknown; Vikings coach Kevin O'Connell is scheduled to give a news conference at 3 p.m

“Obviously it hurts,” right tackle Brian O'Neill said after the game at SoFi Stadium. “Any time you lose one of the best players at his position in the NFL for any period of time, even just a half, it will be felt. We have to lift him up. He knows that he has a lot of support here. He knows that he will be a really good player here for a long time. I’m thinking about him right now and praying for him.”

The Vikings offense must find a way forward without a franchise cornerstone. Darrisaw was rewarded with a four-year, $76 million contract in July as the front office prioritized contract extensions with him following receiver Justin Jefferson's mega-deal in June.

David Quessenberry, a 34-year-old journeyman originally signed before last season, replaced Darrisaw for the remainder of the game and was expected to start in his place on Nov. 3 against the Colts.

Referring to the play in which Darrisaw was injured, O'Connell explained his decision to call a run instead of a pass 35 seconds before halftime from the Vikings' 3-yard line. They had three timeouts available.

“Sean (McVay) had another timeout,” O’Connell said. “In this situation we were on the safe side in the end. They had (six defensive backs) on the field, so I thought maybe we could make a run… and then maybe take a timeout, restart and try to get some chunks. We have a kicker who can hit him from a long distance.”