Quarterback Russell Wilson, the highest profile player that the Pittsburgh Steelers acquired in the offseason, did not practice on the first day of training camp Thursday.

Coach Mike Tomlin said Wilson, 35, woke up with tightness in his calf. He attended practice but wore a baseball cap and T-shirt while the rest of his teammates took part in the 90-minute workout at Saint Vincent.

“Starts aren’t always ideal, but that’s life,” Tomlin said. “It was my decision to sit him down and create a little short-term discomfort for him, not allowing a small problem to become a bigger problem.”

Tomlin said Wilson’s absence could be characterized as day to day. Justin Fields, another newcomer to the quarterback room, replaced Wilson and took first-team reps Thursday. Kyle Allen was elevated from the third spot to the backup position, and undrafted free agent John Rhys Plumlee saw snaps as the No. 3 quarterback.

“It was awesome for Justin and a challenge for our offensive unit to deal with some adversity from the outset,” Tomlin said.