Heller tossed 1.2 scoreless innings in Thursday's spring training contest.
Heller's now up to six innings in five spring appearances, a stretch in which he's yielded just one run while striking out six. The 25-year-old was up for a cup of coffee in the big leagues last season and is still in the mix for a bullpen job heading into Opening Day, but even if he does win a spot, it will likely be in a fairly low-leverage role.