Feltner (shoulder) allowed five runs (three earned) over 2.2 innings in his first rehab start with Triple-A Albuquerque on Wednesday.
Feltner has missed most of August with a right shoulder strain but looks to be nearing a return. He got his pitch count up to just 49 in Wednesday's outing, so it's possible the Rockies will want him to make one more appearance before re-inserting the right-hander into their rotation.