Kaczur, a starting right tackle who was moved to left guard in 2010, sustained a back injury early in training camp and reportedly had back surgery in August. He had been sidelined since.
The Patriots had kept a roster spot open for Kaczur with the hope that he might return at some point. Either it became clear that Kaczur wouldn't return or the Patriots felt they had other roster issues that trumped waiting for Kaczur.
In Kaczur's absence, five-year veteran Dan Connolly has stepped in at left guard and the line has held its ground. The top backup has been second-year player Ryan Wendell and the Patriots re-signed five-year veteran Quinn Ojinnaka last week.
It is also possible that two-time Pro Bowler Logan Mankins, who has stayed away from the team in a contract dispute, will return to the Patriots at some point. Mankins was the team's starting left guard from 2005 to 2009.
Mike Reiss covers the Patriots for ESPN Boston. You can follow him on Twitter.