The New York Mets placed catcher Francisco Alvarez on the 10-day injured list Tuesday with a right thumb UCL sprain.
The move was retroactive to Monday and deprives the Mets of a power bat as they seek to solidify their playoff position.
Alvarez was hurt sliding into second base during Sunday night's victory over Seattle in the Little League Classic in Williamsport, Pennsylvania. He did not travel with the team for Tuesday's series opener at Washington, instead returning to New York to be evaluated.
The Mets said Alvarez would be re-evaluated in 10 to 14 days for a potential return.