Sullivan will start for the Rockies against the Giants on Saturday.
Sullivan is currently with Triple-A Albuquerque but will be recalled by Rockies to serve as the big club's starter Saturday after Tomoyuki Sugano was scratched due to back spasms. Sullivan has started in four major-league games this season, posting an 0-2 record with an 8.64 ERA, 1.86 WHIP and 12:9 K:BB across 16.2 innings. He hasn't been much better in Triple-A, logging a 5.76 ERA and 1.57 WHIP over 54.2 innings (11 starts).