Heller was optioned to Triple-A Scranton/Wilkes-Barre on Wednesday.
Heller was fighting for a low-leverage relief role on the Yankees' Opening Day roster, but it turns out there simply wasn't enough room in the team's already stacked bullpen. The 26-year-old doesn't have much left to prove in the upper minors, as evidenced by his 2.88 ERA, 0.98 WHIP and 13.1 K/9 across 56.1 innings with the RailRiders last season, so he'll likely be shuttled from the minors to the big club when additional relief help is needed.