PITTSFORD, N.Y. (AP) — Linebacker John DiGiorgio was waived by the Buffalo Bills today for failing his physical after having season-ending surgery to repair bone damage in his right knee.

The move was announced after DiGiorgio was absent from practice as the Bills opened training camp in suburban Rochester.

Though the team did not provide any more details, the player's agent, Chris Murray, told The Associated Press that his client had microfracture knee surgery two weeks ago in Vail, Colo. Murray said the surgery went well, but that DiGiorgio isn't expected to be fully healthy until January.

DiGiorgio appeared in six games primarily on special teams before tearing a ligament in his right knee while blocking on a punt return in the second quarter of a 23-14 win over San Diego in Week 7 last season.

Though re-signed by the Bills in February, DiGiorgio did not take part in any of the team's spring practices while recuperating from the knee injury.

DiGiorgio's best season came in 2007, when he made 14 starts, including 13 at middle linebacker, and finished second on the team with a career-high 137 tackles and a pair of sacks.

Receivers James Hardy and C.J. Hawthorne opened training camp on the active/physically-unable-to-perform list as they continue to recuperate from injuries. Hardy, the Bills second-round pick last year, finished last season on injured reserve after tearing a knee ligament in December. Hawthorne had surgery on his left foot in June.

Coach Dick Jauron said he expects both players will soon be cleared for practice.