Chicago Cubs starter Cade Horton threw just 17 pitches on Friday before leaving a start against the Cleveland Guardians with forearm discomfort.

The second-year major leaguer who finished second in Rookie of the Year voting last year was making his second start of the season.

The Cubs announced Horton’s injury after his exit in the second inning. The extent of his injury wasn’t immediately clear.

This story will be updated.