Having already added at least three new defensive starters through free agency, the Buffalo Bills continued to build quality depth on Thursday, with ESPN.com learning that the club has reached an agreement with unrestricted veteran Dainon Sidney.

The five-year veteran spent his entire previous career with the Tennessee Titans and knee and forearm injuries have limited him to five appearances over the past two seasons. Sidney drew surprising interest, however, during the signing period, and rejected offers from the Atlanta Falcons and Detroit Lions to join the Bills instead.

Contract details were not immediately available. One of the team pursuing Sidney, though, was interested in actually guaranteeing a portion of his base salary for 2003.

The interest in Sidney, who played collegiately at Alabama-Birgmingham, is a tribute to the fact there are teams that still feel that, at age 27, he can yet be a solid defensive back. He has the kind of size (6-feet-0, 185 pounds) teams seek at the position and, even after the spate of injuries, runs well.

Sidney chose the Bills, in part, because of his familiarity with coach Gregg Williams, who was the defensive coordinator under whom he first worked at Tennessee. He is also a close friend of defensive back Izell Reese, a former teammate at Alabama-Birmingham, and a veteran who also signed with the Bills as a free agent two weeks ago.

Given the makeup of the Buffalo roster, Sidney should have a chance to vie for the "nickel" cornerback spot, and could win it if he can stay healthy. He certainly demonstrated great promise his first two seasons with the Titans, and was expected to challenge for a starting job in 2001, when he sustained a serious knee injury in the season opener.

Buffalo officials agreed they are betting that Sidney will return to his prior form in 2003 and allow that, if that occurs, they got a steal.

In five seasons, Sidney has appeared in 48 games and started five of them. He has 73 tackles, six interceptions and 16 passes defensed. He picked off three passes each in 1999 and 2000 and had 11 passes defensed, playing as the No. 3 cornerback, in 1999.

Len Pasquarelli is a senior writer for ESPN.com.