David Wright was released from the Hospital for Special Surgery Sunday after he suffered a concussion.
The Mets third baseman was hit with a ball thrown by San Francisco Giants righthander Matt Cain in the fourth inning of Saturday's game.
A team spokesman said he'd gone home and that he had "post-concussion symptoms and a headache."
Wright has now been placed on the 15-day disabled list.
Manager Jerry Manuel could not answer if Wright would be out for the remainder of the season.
"It's going to depend on the tests," he said. "If there's any question, it's a possibility."