KANSAS CITY, Mo. -- Royals rookie right-hander Yordano Ventura will skip his Wednesday start because of a sore back.

"After his last start, he started experiencing some mid-back tightness and some little soreness," Royals manager Ned Yost said. "It's gotten better over the last couple of days, but it's something we really don't want to push. It's a precautionary. We think it's better to bang him one start and go from there."

Yost said a MRI detected "a little fluid back there, which is a sign of inflammation, but no damage at all."

Ventura is 10-9 with a 3.40 ERA in 25 games, 24 of them starts. He also missed a start earlier in the season with a tender elbow.

The Royals are optimistic Ventura will miss just one start and not have to go on the disabled list.