Green was optioned to Triple-A Scranton/Wilkes-Barre on Wednesday.
Green has allowed seven runs on five hits and two walks while recording just one out over his past two appearances, so he'll head to the minors for the time being to figure things out. The right-hander compiled a 2.50 ERA and 94 strikeouts across 75.2 innings last season, so he figures to rejoin the big-league bullpen after working out some kinks. Stephen Tarpley was recalled from the minors in a corresponding move.