Del Castillo (back) is 5-for-17 with three walks and two runs scored in four games with Triple-A Reno since being activated from the 7-day injured list Tuesday.
Del Castillo landed on the 7-day injured list June 20 due to lower back discomfort but was only shut down for one week before gaining clearance to embark on a rehab assignment. He's batting .294 with two home runs, eight RBI and 10 runs through nine appearances this season for the Aces.