The Mets announced the move on Friday ahead of a three-game series in Seattle. New York activated infielder Neil Walker from the 10-day disabled list to take Rivera's spot. Walker has been out since mid-June with a hamstring injury.
The move with Rivera is retroactive to Thursday after he was unable to play in the series finale against San Diego due to the injury. Rivera has received a platelet-rich plasma injection in the elbow and will be re-examined in a couple of weeks to determine if surgery will be the best course of action.
Rivera was batting .290, fourth best among rookies in the National League.