A league source told ESPN NFL Insider Adam Schefter Monday night that he would sign his restricted free agent tender worth $1.54 million after not reporting to the team this year.
Mankins was originally offered a tender worth $3.26 million. When he failed to sign the tender by midnight on June 14, the Patriots reduced the tender to $1.54 million, which will be further reduced because it will be prorated over the remaining nine games of the season.
Coach Bill Belichick was happy to have Mankins back.
"Logan came in, I met with him this morning, and it's good to have him back on the team," Belichick said. "He's been a great player and person for our football team. He's tough. He's smart. You just can't have too many guys like that on your football team. We're glad he's back."
The Patriots will receive a two-game roster exemption for Mankins, according to an NFL spokesman. That means that the team doesn't have to release a player for two games once Mankins signs his one-year tender.
However, if Mankins is active for one of the next two games, the exemption would be lifted at the time he is activated. A roster move would then have to be made to create room for him.
This is standard operating procedure for the NFL when it comes to late-reporting players like Mankins. Teams can only have 53 players under contract on their active roster. With the exemption, the Patriots could have 54 for the two-game stretch.
Belichick and director of player personnel Nick Caserio explained that Mankins' playing status is day to day and that the players that perform best in practice will play in Sunday's game in Cleveland.
The Patriots have the best record in the league at 6-1, without one of Tom Brady's primary blockers from the past. Dan Connolly has become the starter at left guard for an offensive line that has allowed only 12 sacks this season.
Running backs coach Ivan Fears, whose group figures to benefit from the arrival of the two-time Pro Bowler, expressed excitement at Mankins' return.
"The guys are jumping for joy," he said of his running backs. "Having another playmaker like him coming back to us, we're kind of excited about it. Plus, he's fresh."
Mankins would have been an unrestricted free agent under the rules of the last collective bargaining agreement. However, when the owners opted out of the deal, triggering 2010's uncapped year, only players with six years in the NFL gained unrestricted status. By signing now, Mankins assures himself a chance at becoming an unrestricted free agent in the offseason.
Information from ESPNBoston.com's Mike Reiss was used in this report.