 In 46 total innings with St. Louis in 2016, Reyes struck out 52; his 1.57 ERA ranked second among all major league rookie relief pitchers with at least 20 innings.On February 14, 2017, Reyes was diagnosed with a partial tear of his ulnar collateral ligament in his right elbow.The next day, it was announced Reyes would undergo Tommy John surgery, shelving him for the entire 2017 season.