According to Adam Schefter of ESPN, wide receiver Doug Baldwin suffered a Grade 2 partial MCL tear. Schefter noted the Seahawks are still attempting to determine an official timetable for his return.
Baldwin suffered the injury when Broncos defensive tackle Domata Peko rolled up on his leg during a play.
Seattle head coach Pete Carroll talked about his receiver's status after the loss and before the Grade 2 partial MCL tear ruling, per the Seahawks' official website.
"He's got a little MCL sprain in his other knee, so we've just got to see what that means," Carroll said. "He went back in the game and played some, eventually kind of talked him out of playing because he wanted to keep going, just to make sure we take care of him."
Baldwin played a full 16 games in six of his seven seasons in the league and missed just two contests in 2012.
He has been an integral part of the Seahawks' passing attack, especially of late, and tallied 75 catches for 991 yards and eight touchdowns last season after combining for 2,197 receiving yards and 21 touchdown catches in 2015 and 2016.
Wilson threw three touchdowns but also two interceptions in the loss without his presumed top target on the field for much of the game and will likely turn toward Tyler Lockett and Brandon Marshall more moving forward if Baldwin is sidelined for significant time.