Arano was optioned to Triple-A Lehigh Valley on Saturday.
Arano had a brutal spring. Opposing hitters hit .654 against him as he allowed a whopping 20 runs in just four innings of work and finished with a 1:7 K:BB. The 24-year-old could still spend the bulk of the season in the majors if he can get back to the form which led him to a 2.57 ERA through 70 career big-league innings, but he clearly has to sort things out in the minors before returning to Philadelphia.