Harrison was injured during Monday's 41-7 win over Denver. The injury as original believed to be to his right knee but The Boston Globe and NFL.com both citing unnamed league sources, said Harrison had the muscle injury and that he would miss the rest of the season.
New England Coach Bill Belichick, who is always circumspect about injuries, Tuesday said: "It was difficult for all of us to watch Rodney get carted off like he did. When we have some more information, we'll give it to you."
Harrison, 35, is in his 15th NFL season, having played nine seasons with San Diego before joining the Patriots in 2003. He is the only NFL player with 30 sacks and 30 interceptions in his career. Harrison has been selected to the Pro Bowl twice.
New England also saw running back Sammy Morris leave Monday's game because of a knee injury. His status wasn't known Tuesday.