Anderson will start Saturday's game against the Diamondbacks, Thomas Harding of MLB.com reports.
He'll take the rotation spot of Kyle Freeland (collarbone), who has struggled in a trio of September starts. He compiled a 6.21 ERA and 1.54 WHIP in 12 starts for the Rockies earlier in the season, so he isn't a lock to stick in the rotation past Saturday. Anderson has made just one appearance for the big club since injuring himself June 25, tossing four scoreless innings of relief Monday, so he's expected to be limited to around 70 pitches in his return to the rotation.