Agnos will serve as the Rockies' opening pitcher for Thursday's game against the Diamondbacks, Thomas Harding of MLB.com reports.
Tomoyuki Sugano had been on track to start Thursday, but he'll instead be pushed back to Friday while the Rockies opt for a bullpen game in the series opener. The upcoming start will be the first of Agnos' professional career, as he's worked exclusively as a reliever and in the minors and in 43 appearances with the Rockies over the past two seasons. Agnos should be capable of providing more length than the typical opener, however, as he's already covered four-plus innings on three different occasions this season.