Rosenthal will require Tommy John surgery to repair his elbow, Derrick Goold of the St. Loius Post-Dispatch reports.

EDGE Analysis

This is tough news for Rosenthal, as a second opinion from Dr. Neal ElAttrache confirmed he's dealing with a tear of the ulnar collateral ligament in his right elbow that will require surgery to repair. The good news is he's not dealing with a total UCL rupture, according to David Solomon of 550 KTRS, though his status for 2018 remains up in the air. Seung Hwan Oh should now be first in line for saves in St. Louis for the remainder of the season.