Arizona Cardinals tight end Zach Ertz is out indefinitely with a knee injury suffered early in Sunday’s win over the Los Angeles Rams, but he will get a second opinion and the injury could be season-ending.

Cardinals coach Kliff Kingsbury said during his press conference Monday that the team expected to have a better picture of Ertz’s injury later Monday or sometime Tuesday.

Ertz went down in the first quarter and walked off gingerly under his own power but put his head in his hands in one point. Teammates came over to him to slap his shoulder pads and give him high fives in support. After being evaluated in the blue medical tent, Ertz was carted to the locker room.

Ertz had 406 yards and four touchdowns on a team-high 47 catches before his injury.