Pittsburgh Steelers rookie quarterback Will Howard exited practice early on Tuesday, just days before he was set to make his preseason debut.

Per Brendon Howe of Steelers Now, Howard was taken back to the locker room on a cart midway through practice.

“The Ohio State product was taken back toward the locker room at St. Vincent College while sitting in the front of a cart with a trainer. The reason for the early exit is unclear,” Howe wrote. “Howard, a Steelers training camp darling, had climbed ahead of [Skylar] Thompson during team sessions. Howard was listed as the team’s No. 3 passer on the team’s initial depth chart, posted Tuesday.”

The injury comes at an unfortunate time for the sixth-round pick, with the Steelers set to travel to play the Jacksonville Jaguars on Saturday in Week 1 of preseason play.

Howard, who led Ohio State to a victory in January’s national championship, is fighting to earn a spot on the 53-man roster. He must have a strong showing in the preseason, like he’s had in the early days of training camp, to make a case to stay on the team or risk being waived before potentially signing with the practice squad.

Following Howard’s departure, Howe noted that Thompson stepped in to take third-team reps. Mason Rudolph was working with the second-team offense, while veteran Aaron Rodgers was with the first-team offense.

Howard was born and raised in West Chester, Pennsylvania, and attended Downingtown West High School. He’s considered a “fan favorite” as a native of the Steelers’ home state.