The Mets placed Alonso, whose 22 home runs lead the majors, on the 10-day injured list Friday, retroactive to June 8. Alonso was hit in the wrist by a 96 mph fastball from Charlie Morton in the first inning of a 7-5 loss to Atlanta on Wednesday.
Alonso travelled to New York for testing on Thursday. X-rays revealed no broken bones, but the Mets will be missing one of the premier power hitters in the game as they try to work their way back into contention in the NL East.
New York had lost six straight heading into a three-game series at Pittsburgh that began Friday. Mark Canha started at first for the Mets in the opener.
The team also said Friday that reliever Edwin Uceta had surgery to repair a torn meniscus in his left knee. Uceta initially went on the IL in April with what the team called a sprained left ankle. He is expected to be out for at least an additional eight weeks.
New York recalled infielder Luis Guillorme and left-handed reliever Zach Muckenhirn from Triple-A Syracuse. The Mets sent catcher Tomás Nido to Triple-A and designated reliever Stephen Nogosek for assignment.
Nogosek is 0-1 with a 5.63 ERA in 13 games this season.