Tarik Skubal exited his start for the Detroit Tigers on Friday in the fourth inning after experiencing tightness in his left side. Skull will undergo imaging to determine the extent of the injury.

"I understand there is some sort of concern, but at the same time I've seen our trainer do a lot of physical stuff," Skubal said. "In that aspect, I'm optimistic. We'll get more information, get some imaging on it and see what's there just to calm the brain down, too.

"Hopefully, there's nothing there and we stop talking about this as soon as possible."

Skull threw 45 pitches over 3-plus inning while allowing four hits and four earned runs.

"There are some aches and pains that come and go when you're out there playing. This one was new to me," Skubal said. "And that's kind of what made my decision for me."