The Chicago White Sox placed Cy Young candidate Carlos Rodon on the 10-day injured list with left arm soreness, the team announced Wednesday.
Rodon, 28, is 9-5 with a 2.38 ERA in 19 starts this season and could be out longer than the required 10 days.
"We're going to err on the side of caution so it seems to me that's overly optimistic," White Sox manager Tony La Russa said. "If it happens great, if it doesn't, we'll be patient."
Rodon reported the soreness on Tuesday while the team was in Minnesota for a road series.