Adam Thielen underwent season-ending ankle surgery this week, leading to the Vikings placing him on injured reserve Wednesday.

The veteran receiver tried playing despite high ankle sprain suffered Dec. 5 when Lions cornerback Jerry Jacobs landed on Thielen's left leg. He returned three weeks later against the Los Angeles Rams, aggravating the injury in the second quarter when he was tackled low.

"Hope he heals up good," running back Dalvin Cook said, "get everything intact and get it right. Since I got here, he's been a true brother; true meaning of brother, not even football-related. Just being there for me. So I'm going to do the same for him, whatever he need. We're going to miss him out there."

Receiver K.J. Osborn is expected to replace Thielen for the third time Sunday in Green Bay, where the Vikings (7-8) need to win to keep their playoff chances attainable.

"Adam was battling through an injury and showing his toughness by playing against the Rams," quarterback Kirk Cousins said. "We'll have to ask that much more from some of our other receivers."

Osborn has emerged as a reliable No. 3 option behind Justin Jefferson and Thielen, with 46 catches for 584 yards and five touchdowns this season. He had a rough moment last week, tipping a Cousins pass which the Rams intercepted in the red zone.

Without Thielen, the Vikings will be missing a leader in production and energy coming off a loss in which Jefferson said the team lacked liveliness.

"He's that vocal guy," Cook said. "That guy that brings that juice every day. You can expect that same Adam every day. I'm going to miss him. There really haven't been too many games where I've touched the field without him since I got here."