Smith was designated for assignment by the Diamondbacks on Thursday, Steve Gilbert of MLB.com reports.
After going 0-for-4 with a strikeout Wednesday in San Diego, Smith has been cut loose from Arizona's 26-man and 40-man rosters. The 30-year-old has slashed just .141/.236/.192 with one homer and six RBI in 89 appearances this year. Smith had slowly been losing time at first base to Ildemaro Vargas and Tim Tawa. The Diamondbacks recalled Ryan Waldschmidt from Triple-A Reno to replace Smith on the active roster.