Smith is expected to take on the designated hitter spot most of the time against right-handers, Alex Weiner of Arizona Sports reports.
That was Smith's job Monday, when he was activated off the 60-day injured list. He was on the bench for Tuesday's game against Dodgers lefty Eric Lauer but entered as a pinch hitter against a right-handed reliever. Smith's return mostly affects Adrian Del Castillo but could also eat into Ildemaro Vargas's playing time at first base.