Quintana (elbow) will begin a rehab assignment at Double-A Hartford on Wednesday, Kevin Henry of The Denver Gazette reports.
Out since late May with a sprained left elbow, Quintana began his throwing program in early July and has finally reached the final stage in his rehab. The Rockies -- already eliminated from postseason contention -- likely won't be in much of a hurry to bring the veteran southpaw back, but he could still return in time to make another start or two before the end of the season.