Tom Curran of Comcast SportsNet New England confirmed that Carpenter is headed back to the Patriots. That's not a good sign for rookie Dont'a Hightower, who left last week's win over the Buffalo Bills with a hamstring injury.
Carpenter was a surprise cut by New England after a reportedly strong training camp. The Patriots' defense has looked a lot better this year, especially at linebacker with Hightower and a healthy Brandon Spikes.
New England's defense gets another tough test this week in Foxborough against Peyton Manning and the Denver Broncos. Week 5 does not have a slate of terrific games, but Manning-Brady might be the game we've been looking forward to most all season.
UPDATE: The Patriots later announced the signing of Carpenter. The team released defensive lineman Terrell McClain to clear roster space for the linebacker.
Follow Gregg Rosenthal on Twitter @greggrosenthal.