Warren was placed on the 15-day injured list Tuesday with a nasal fracture, Jeff Fletcher of The Orange County Register reports.
Warren suffered the injury during batting practice Tuesday, as he was struck in the face by a stray ball. The 25-year-old has a 4.32 ERA, 1.56 WHIP and 5:5 K:BB through 8.1 innings this season but will be unavailable for at least the next 15 days.