Arizona will be without one of its top defenders Saturday when it hosts the Colorado Buffaloes.

Coach Jedd Fisch said on Thursday that safety Jaxen Turner is “unlikely” to play in the game after a shoulder injury suffered against Cal. Turner has started all four games to begin the season. In his place, Isaiah Taylor will start.

Taylor has seen 58 snaps with appearances in all four games.

The fourth-year junior is the highest-graded safety in the Pac-12 so far this season. He’s third on the team in tackles with 24. He also has a pass breakup, a forced fumble, and an interception.

Arizona will be looking for a better defensive effort against the Buffaloes than the one it had against the Golden Bears last weekend. Cal put up 49 points on the Cats, as the defense was misaligned, missing fits, or just missing tackles. If there’s a game to miss and get right, it might be CU, though.

The Buffs are 0-4 to begin the season and have lost each game by at least 25 points. Kickoff is set for 6:30 p.m. PT on the Pac-12 Network.