The Rockies placed Castro on the 10-day injured list Saturday with left heel inflammation, retroactive to Wednesday.
Castro has sat out the Rockies' last three games while managing plantar fasciitis in his left foot, and he'll now officially remain out until at least next Saturday as he recovers. Vimael Machin will come up from Triple-A to replenish Colorado's infield depth, though Connor Norby and Ryan Ritter are more likely to benefit from additional playing time.