"We're excited about it," McCann's agent, John Biggins, said. "We've been talking to the Ravens since he got released from the Cowboys. With the bye week, it's a good time for him to join the Ravens, get up to speed on the playbook and just go forward. We know that the Ravens are a Super Bowl-caliber team and Bryan is excited to be part of it."
To make room for McCann on the roster, the Ravens cut linebacker Prescott Burgess, who had re-signed with the team last week.
McCann, 24, who went undrafted out of Southern Methodist, was released by the Cowboys on Sept. 20. He played nine games for them last season and two this year, receiving credit for 15 tackles and two passes defended.
He made his NFL debut in November, returning an interception 101 yards for a touchdown in the Cowboys' 33-20 victory over the New York Giants in Jason Garrett's head coaching debut. The following week, he ran back a punt 97 yards for a touchdown in a win over the Detroit Lions.
The Ravens are thin in the secondary, and coach John Harbaugh acknowledged late last week that he'd be more comfortable if the team added a cornerback. The Ravens had just four healthy cornerbacks: starters Lardarius Webb and Cary Williams, and reserves Danny Gorrer and rookie Chykie Brown.
McCann spent one week with the Ravens early last season. He was claimed off waivers Sept. 5, but after being inactive for their regular-season opener, he was waived. He then re-signed with the Cowboys.
"They're signing him for him to play," Biggins said of the Ravens. "There's no doubt about that. They've talked to us about him returning kicks and punts, playing on the special-teams units and playing in the nickel. I know they are happy to have him. We wanted a place where he can play, and we feel like the Ravens present that opportunity. He's going there with a mindset to join a great team and help them win games, with the Super Bowl being the ultimate goal."
McCann could boost the Ravens' return game. He averaged 20.6 yards per punt return last season and 22 yards per kickoff return. Rookie LaQuan Williams has been returning kicks and punts, though safety Ed Reed handled punt return duties late in Sunday's game.