Garrett will undergo Tommy John surgery Tuesday to repair the partially torn ulnar collateral ligament in his left elbow, Clark Spencer of the Miami Herald reports.
While Garrett was exploring other possible options for a few days, a second opinion on his elbow from Dr. James Andrews ultimately confirmed he would require surgery. The Marlins' top prospect will look to bounce back after a long recovery process that will keep him sidelined until next season or perhaps until 2019.