The Astros optioned Arrighetti to Triple-A Sugar Land on Monday, Matt Kawahara of the Houston Chronicle reports.
Houston will eventually go to a six-man rotation, and Arrighetti could fill that slot when that happens, per manager Joe Espada. For now, though, the righty will hone his craft in the minors. Arrighetti was limited to only seven starts last season due to injuries and posted a 6.75 ERA and 12:5 K:BB over eight innings this spring.