The Patriots released Watson on Oct. 7 because the team didn't have an open roster spot after his return from a four-game suspension for performance-enhancing drugs. Due to injuries, New England opted to work out a deal with the veteran pass-catcher, who spent training camp with the club.
Watson's return comes after the Patriots lost fullback Jakob Johnson to a shoulder injury and tight end Matt LaCosse to a knee injury in Thursday's win over the New York Giants. Wide receiver Josh Gordon also sustained a knee injury against New York.
New England announced Monday that the team placed Johnson on injured reserve, freeing up a roster spot for Watson.
Watson, 38, will join LaCosse and second-year pro Ryan Izzo as tight ends on the Patriots' roster. Watson recorded 35 receptions for 400 yards and two touchdowns with the New Orleans Saints last season.