Plummer signed a one-year contract with the Mets on Wednesday.
Plummer elected minor-league free agency in early November and will land a big-league contract ahead of the 2022 campaign. The 25-year-old hasn't yet made his major-league debut but should compete for a depth role with the Mets during spring training. He was one of the top minor-league free agents on the open market after he slashed .280/.415/.479 with 20 doubles, six triples, 15 homers, 54 RBI, 71 runs and 13 stolen bases in 117 combined games between Triple-A Memphis and Double-A Springfield.