An MRI revealed the extent of the injury a day after he went 0-for-3 in a spring game against the Yankees.
"I'm not sure if it was one [play]," Showalter told reporters. "I'm just reporting what the MRI said. This guy was doing everything on the fields -- running full speed. That just tells you how different actual game speed is. He was fine during the game doing everything, for the most part. He said he was driving home last night and started to get stiff and sore. They decided to get a picture this morning, and that's the results."
Trumbo was hitting .130 this spring, with three hits in 23 at bats.