(BCSNN) — Arizona State quarterback Sam Leavitt will miss Saturday’s game against Iowa State as he continues to battle a lingering foot injury that has hampered him since the Sun Devils' game against Baylor in late September.

Leavitt twice exited last week’s loss to No. 22 Houston, first after a hard hit in the opening quarter and again in the fourth after limping off the field. He was seen in a walking boot at Tuesday’s practice, and head coach Kenny Dillingham confirmed the injury has persisted throughout the season.

“It hasn’t progressed like we hoped,” Dillingham said. “He hasn’t been at full speed, so we’ll reassess it during the bye and make a decision from there.”

Leavitt first injured the foot against Baylor on Sept. 20 and missed the Utah game two weeks later. He returned to lead the Sun Devils to a comeback win over No. 13 Texas Tech on Oct. 18, but the injury flared up again against Houston.

Backup Jeff Sims is expected to start against the Cyclones. Sims went 6-for-11 for 58 yards in relief last week and previously started against Utah.

Leavitt has thrown for 1,628 yards, 10 touchdowns, and three interceptions this season after leading Arizona State to its first College Football Playoff appearance last year.