Lopez (undisclosed) was removed from Thursday's game in the fifth inning, Scott Merkin of MLB.com reports
Merkin adds that there was a strange sequence in the lead-up to Lopez's removal as the training staff came out for a mound visit, went back to the dugout, then returned after the next batter to pull the young righty from the game. Lopez managed to fan six batters in just 4.1 innings, but his command was erratic as he surrendered four earned runs and also walked four batters. More information on Lopez will likely be made available Thursday or early Friday, but this is concerning given that Lopez is considered to be a key piece of Chicago's revamped core moving forward.