Collins announced his retirement from the NFL on Friday, Daniel Chavkin of SI.com reports.
Collins reverted back to the Patriots' practice squad Tuesday.
Collins signed with the Patriots' practice squad Monday, Evan Lazar of the team's official site reports.
Collins was signed by the Patriots on Monday, Andrew Callahan of the Boston Herald reports.
Collins (ankle) is listed as active Saturday in Buffalo.
Collins (ankle) was a limited participant at Thursday's practice.
Collins was activated from injured reserve by the Patriots on Monday, Mike Reiss of ESPN.com reports.
Collins (ankle) was spotted practicing Wednesday, Zack Cox of NESN.com reports.
Collins (ankle) was placed on injured reserve Saturday.
Collins (ankle) is listed as doubtful ahead of Sunday's game against the Browns.