Sheriff's Detective Dennis Sullivan says Collier remains in critical but stable condition at a Jacksonville hospital, with multiple gunshot wounds. He was shot in his car outside an apartment last Tuesday.
Sullivan refused to give any other details about the investigation.
Sheriff John Rutherford also said police do not believe the shooting was the result of any earlier confrontation at a nightclub.
Police said Collier's teammates and friends added $10,000 to the usual $1,000 reward for information on the assailant.