Hartlieb was optioned to Triple-A Indianapolis on Friday.
Hartlieb didn't do much in his 35-inning debut last season to suggest he should open this year in the big leagues. He posted a 9.00 ERA and 2.00 WHIP. His .411 BABIP and 59.5 percent strand rate suggest he got rather unlucky, but he'll need more than a rebound in his luck to be an effective reliever this season.