The Cubs selected Greene's contract from Triple-A Iowa on Sunday, Meghan Montemurro of the Chicago Tribune reports.
Greene was designated for assignment by Chicago in early September, but he'll rejoin the 40-man roster for the final game of the season. The veteran right-hander delivered a scoreless frame in his lone big-league appearance of the season and posted a 1.75 ERA over 25.2 innings at Triple-A.