DeGraw tweeted Tuesday afternoon that he didn't remember much of Sunday's beating. Police say DeGraw was attacked by a group of men in the East Village. No arrests have been made yet.
A representative says the 34-year-old DeGraw also suffered black eyes, cuts and bruises.
DeGraw canceled concerts this week in upstate New York and Massachusetts after the assault.
On Twitter, DeGraw thanked fans and said: "I only know I can recover from here. ... I love u guys."
DeGraw's new album, "Sweeter," due out in September. His top hits include "Chariot" and "I Don't Want to Be."