A spokesperson for the 'I Don't Want to Be' singer confirmed that DeGraw suffered multiple injuries from Sunday's incidents, including a concussion, broken nose and black eyes, as well as cuts and bruises, E! News reports.
"Gavin and his family appreciate everyone's concern at this time," said DeGraw's publicist.
DeGraw was hospitalised on Sunday after being assaulted by numerous assailants on the streets of New York City. In addition, the singer was reportedly hit by a passing cab while trying to escape the attackers.
Police are currently investigating the incident, but the motive behind the assault remains unknown at the moment.
DeGraw had been scheduled to perform with Train and Maroon 5 in Saratoga Springs, NY tonight. There is no word on who will take over his duties as the opening act for the two bands.
The singer is currently recovering at Bellevue Hospital in New York City.
Watch Gavin DeGraw perform 'Chariot' below: