The cornerback from Rutgers received a deal worth $13.2 million with $7.825 million guaranteed, according to his agent, Andy Simms.
Patriots rookies were due to report Sunday, but the first full-squad workout is set for Thursday morning. McCourty, who is expected to compete for a starting job, was eager to report by Wednesday, when veterans were due at 7 a.m. Simms said McCourty signed his contract at about 7 a.m.
"We worked pretty late (Tuesday) to get to this point," Simms said. "We know what's important in New England and that's to get to camp on time."
The negotiations took place with the possibility of a lockout in 2011 if management and the players' union can't agree on a new collective bargaining agreement.
"The pending labor situation is something we had to consider," Simms said. "We worked with the Patriots on some of the issues."
McCourty is expected to challenge Darius Butler, the 41st overall draft pick last year, for a starting spot in New England. Butler started five of the 14 games in which he played last season and made three interceptions. In four seasons at Rutgers, McCourty had six interceptions and started the last 39 games at cornerback. He also blocked six punts and a field-goal attempt.
Leigh Bodden, who's entering his eighth NFL season and second with the Patriots, is the team's other starting cornerback.
Crable never played in a regular-season game for the Patriots, who drafted him in the third round from Michigan in 2008. He was inactive for the first eight games as a rookie before going on injured reserve because of an injured shin. He also spent last season on injured reserve after hurting his groin.
Crable's release came one day after he was placed on the active physically unable to perform list and one day before the opening of training camp.
The Associated Press contributed to this report.