Busenitz was sent to Triple-A Rochester on Sunday, Brandon Warne of ZoneCoverage.com reports.
Busenitz was optioned to make room for Adalberto Mejia, who's slated to start Tuesday's matchup against the Blue Jays. In 10 appearances out of the bullpen this season, Busenitz has accrued an ugly 6.75 ERA and 2.08 WHIP with 15 strikeouts over 12 innings.