The 23-year-old pitcher was called up on June 5 to fill in while Raisel Iglesias recovers from a strained oblique. Moscot made his third start on Monday in Detroit and dislocated his left shoulder in the first inning when he dived to tag baserunner Anthony Gose.
Cincinnati manager Bryan Price said on Thursday that tests found instability in the shoulder and Moscot will have surgery soon. He's expected to be fully recovered by spring training.
Moscot was 1-1 during his brief stint with the Reds, giving up 11 hits and six runs in 11 2-3 innings.
Follow Joe Kay on Twitter: http://twitter.com/apjoekay