The Mets placed Young on the 7-day concussion injured list Friday, Anthony DiComo of MLB.com reports.
Young's season is over after he had to be taken off the field on a stretcher in Thursday's game versus the Phillies after taking a knee to the head on a play at first base. He is dealing with concussion symptoms including short-term memory loss and bad headaches, but interim manager Andy Green said that Young is doing "as good as expected or could be hoped for."