Santana (thigh) began a rehab assignment in the Arizona Complex League on Friday, Alex Weiner of Arizona Sports reports.
Santana started at first base, played five innings and went 2-for-3 with a home run and two RBI. He was back at Chase Field to take batting practice with the Diamondbacks on Saturday. It's unclear what role Santana will have once he's ready, as first base and DH are crowded with Pavin Smith, Ildemaro Vargas and LuJames Groover all looking for playing time. That list doesn't include the imminent returns Lourdes Gurriel (hamstring) and Jordan Lawlar (wrist), both of whom may need at-bats at DH.