"He's getting Tommy John because he needs it," Cashman said. "That's the bottom line. Obviously, he was feeling it regardless of getting back. I think we tried to address this in the past, but you know when he had the in-season injury, there was a rest and rehab process that was put in play. That process failed because the pain immediately came back.
"[Hicks] played a great force in the postseason, but once it ended [for us], there was the feeling of, 'There's something here that's still not right.' The follow-up doctor exam led to the ultimate decision that we've got to get this thing fixed or it's just going to blow in February, March or April."
Hicks, who missed about two months near the end of the regular season due to the injury, returned to the team for the American League Championship Series against the Houston Astros. He went 2-for-13 in the series, but his three-run homer in Game 5 helped the Yankees avoid elimination and force Game 6.
Hicks, 30, had a .235 batting average with 12 home runs in 59 games this season.
Cashman also announced that right-handed pitcher Masahiro Tanaka underwent arthroscopic surgery to remove bone spurs in his pitching elbow. First baseman Luke Voit also had surgery to repair a core muscle injury.