The 29-year-old Lamb looked like a future star at third base just a few years ago. He hit 29 homers in 2016 and then made the NL All-Star team in 2017 while setting career-highs with 30 homers and 105 RBIs. Since then, he's battled injuries and inconsistency and hit just 12 homers over the past three seasons.
He didn't get much playing time for the D-backs this season and had just five hits in 43 at-bats for a .116 average. He had a prorated salary of $2,042,593.
The team made the move on Thursday and thanked Lamb for his seven years in the desert on social media.
Lamb's spot on the roster was taken by first baseman/outfielder Pavin Smith, who was the No. 7 overall pick in the 2017 draft. The 24-year-old Smith, who played in college at Virginia, will be making his major league debut.