Buffalo Bills coach Sean McDermott announced on Thursday that linebacker Matt Milano is out indefinitely and will miss at least the first few months of the season with a torn left bicep. It's just the latest setback for Milano after missing the majority of last season with a broken leg.

McDermott provided the update as the Bills prepared to hold a joint practice with the Steelers, two days before the teams play a preseason game in Pittsburgh. Milano is scheduled to have surgery and, barring complications, has a chance to return by December.

Milano was hurt early in practice during a tackling drill on Tuesday, and spent the rest of the session watching from the sideline after being examined by trainers.

"It's an unfortunate situation and he's a strong young man," McDermott said. "He's resilient and we've got to be resilient, and we've got to move forward to work on solutions."

The setback comes as the 30-year-old Milano was being eased back after a complicated injury in breaking his right leg that forced him to miss the final 12 games of last season. He was cleared for practice for Buffalo's mandatory minicamp in mid-June and had been practicing fully through camp, while being held out of Buffalo's preseason-opening 33-6 loss to Chicago last week.

The 2022 All-Pro has been a key cog in the middle of Buffalo's defense since being selected in the fifth round of the 2017 draft out of Boston College. Though relatively undersized at 6 feet and 223 pounds, the 29-year-old's sideline-to-sideline speed and hard-hitting ability has led to him being a three-down player since his rookie season.

Milano's injury further exposes the Bills' lack of experience on defense following an offseason of salary cap-forced turnover, which led to the breakup of the team's veteran secondary. Milano's primary backups are second-year player Dorian Williams and rookie fifth-round pick Edefuan Ulofoshio.

The only backup linebacker on Buffalo's roster with more than two years of NFL experience is Nicholas Morrow, who has missed a large portion of training camp with an ankle injury.

Reporting by The Associated Press.

[Want great stories delivered right to your inbox? Create or log in to your FOX Sports account, follow leagues, teams and players to receive a personalized newsletter daily.]