Castano has been on the injured list since late June due to a pectoral strain. He began playing in rehab games last Saturday and has since allowed four runs on four hits and two walks over 2.1 innings. Now fully healthy, the 27-year-old will remain in Triple-A for the time being but could return to the majors later in the year as bullpen depth.

Castano will need more than a week to build up as he works his way back from a right pectoral strain, so he doesn't appear to be in line to return from the 15-day injured list until after the All-Star break. Before landing on the shelf June 21, Castano turned in a 3.92 ERA, 1.35 WHIP and 17:6 K:BB in 20.2 innings over 10 appearances out of the Colorado bullpen.