The Rockies reinstated Diaz (calf) from the 10-day injured list Sunday. He'll serve as the Rockies' designated hitter and will bat fifth in Sunday's series finale versus the White Sox, according to Luke Zahlmann of The Denver Gazette.
Waldron (5-7) took the loss Sunday against the Red Sox. He gave up four runs (three earned) on six hits, one walk and three strikeouts over 4.1 innings.