Carpenter, 29, was a surprise cut on Sept. 1, one day after the Patriots trimmed their roster to 53 players. The former first-round pick signed with New England in April after stints with the Cowboys, Dolphins and Lions.
Rookie linebacker Dont'a Hightower left Sunday's road win over the Bills in the first quarter with a hamstring injury and did not return. He was replaced by Tracy White, whose contributions mainly come on special teams.
Carpenter has played in 89 career games, making 10 starts. During the preseason, he was the top reserve option at linebacker behind Hightower, Jerod Mayo and Brandon Spikes.
The Patriots have an open roster spot after releasing defensive tackle Terrell McClain on Tuesday.