Tomas had his contract purchased from Triple-A Reno on Friday.
Tomas is set to join the Diamondbacks for the first time since 2017 after compiling a .305/.341/.603 slash line with 29 home runs and 23 doubles across 98 games for Reno. The 28-year-old has split time between first base and left field in the minors, though it remains to be seen what role he'll play with the big club. Tomas, who hit .272 with 31 homers in 140 games back in 2016, could see time at DH during next week's series against the Yankees in New York. To free up a spot on the roster for Tomas, Taylor Clarke (personal) was placed on the paternity list while Luke Weaver (elbow) was shifted to the 60-day IL.