SEATTLE (AP) — The Seattle Seahawks will be without starting quarterback Sam Darnold on Sunday against the Arizona Cardinals because of a quad injury.

Seahawks coach Mike Macdonald announced Wednesday that backup Drew Lock will step in for Darnold. Lock started one game earlier this season against the Cardinals in Arizona and played most of the season opener against the New England Patriots after Darnold suffered a glute injury.

Darnold's most recent injury came during the Seahawks' 34-17 loss to the Chicago Bears on Monday night. He completed 17 of 34 passes for 188 yards, two touchdowns and one interception.

Darnold will not go on injured reserve and will be evaluated on a week-to-week basis, Macdonald said.

Lock has been dealing with a sore elbow that sidelined him for two games and Jalen Milroe has been the backup.

Lock has completed 35 of 48 passes this season for 422 yards and four touchdowns with no interceptions, including a three-touchdown performance in a 31-7 victory over the Cardinals in Week 2.