Cosart underwent arthroscopic surgery on his right elbow this week and will be out for the remainder of the season, Dennis Lin of The San Diego Union-Tribune reports.
Cosart had been rehabbing at the team's spring training complex after being diagnosed with a flexor strain, but the injury appears to have required more of a long-term solution. The righty, who missed the beginning of the season while sidelined with a hamstring injury, finishes the 2017 campaign with a 4.88 ERA over seven appearances (six starts) and an unattractive 15:19 K:BB ratio. He begins the long road to recovery, as Dinelson Lamet takes over his spot in the starting rotation.