FOXBOROUGH -- It is likely the official word will not come from the Patriots until tomorrow, but two team sources told the Globe that safety Rodney Harrison has a torn ligament in his left knee and will miss the remainder of the season.
Harrison, a 12-year veteran, who was injured in the first quarter of Sunday's game at Pittsburgh, underwent an MRI yesterday morning that revealed the most feared result: a tear in the anterior cruciate ligament.
Harrison, who turns 33 in December, is one of the more superbly conditioned athletes on the team, but typical recovery from an ACL injury is 9-12 months. Harrison is the second-oldest starting safety in the NFL, five months younger than the Saints' Jay Bellamy, who coincidentally suffered a rotator cuff injury Sunday and is out for the rest of the season.
Harrison's agent Steve Feldman acknowledged that his client's knee injury could be career-threatening.
''I just keep my fingers crossed, that Rodney does what is in his best interest," Feldman said. ''If that's rehab and coming back that's great. If it's not coming back, that's great, too.
''He certainly hasn't left anything on the table. He's put all he has into the game."
Feldman described Harrison as one of the toughest guys in the league, and said the injury is especially difficult to take because Harrison is playing exceptional football with a championship team.
''The Patriots stepped up and saved his career, and he loved them for it," Feldman said. ''This is the last thing in the world that he could ever thought would happen right now. It's absolutely devastating."
Harrison went down after Steelers receiver Cedrick Wilson was knocked into his leg. With his foot locked into the turf, Harrison's left knee bent inward in an awkward position.
''Rodney's tough as nails and anytime a guy like that goes down in pain on the field, you know there's something wrong," Patriots defensive end Richard Seymour said.
Harrison led the Patriots in tackles in each of his first two seasons with the team, and he was leading them after two games this season.
A team leader in the locker room (he was voted a team captain), Harrison is one of the organizers of a group of veterans who set the team standard with early arrival for workouts, according to teammates.
On the field, Harrison's physical play makes him one of the most feared hitters in the league.
''He's an emotional player," defensive end Ty Warren said. ''You see him out there fighting all the time, that's just kind of his mentality. Everything to him is competitive, he's enthusiastic, and he plays hard on every play.
''We have to continue to play. Obviously he was a big part of this defense, but with him going down, even [Sunday], things can't stop. We just have to continue to do what we have to do. Guys that play his position need to step up and I'm sure they'll do that. They did that yesterday, the best they could."
Second-year safety Guss Scott subbed for Harrison and played all but a couple of plays in the final 3 1/2 quarters. Cornerback Chad Scott lined up at safety when Guss Scott was shaken up midway through the fourth quarter.
''Defensively he did a pretty solid job," Patriots coach Bill Belichick said of Guss Scott. ''There were some things that could've been better and some of the things he ended up having to do in the game he really hasn't practiced a lot because Rodney had taken a lot of those plays.
''But, that's no excuse. Every player has to be prepared. But there are, again, some things that I think with experience he'll probably -- if he's put in that situation again -- do better with the practice reps on. [For instance], the communication with Eugene [Wilson] and the corners and so forth. I thought he did a solid job. But, there's room for improvement."
Another problem is that rookie James Sanders, the only other safety on the roster, has been out for more than three weeks with an ankle injury. He impressed Belichick during training camp. Ray Ventrone is the lone safety on the practice squad, but the undrafted rookie free agent's most likely contribution at this point would be on special teams, not in the regular defense.
Belichick says the Patriots use their safeties interchangeably, though Harrison, the better tackler, is most often the strong safety, while Wilson, who is better in coverage, lines up at free safety.
Wilson said the communication between him and Harrison had reached a point where the two could just look at each other and know what to do.
''He's like a big brother to me out there," Wilson said. ''He's helped me along since I've been here. But we're just going to try and move on."
Wilson was asked about the Patriots' defense now missing the two players most often described as the heart and soul of the unit the past two seasons -- Harrison and linebacker Tedy Bruschi, who is sitting out the season recovering from a stroke.
''Nobody can replace those guys," Wilson said. ''We can only just work with what we've got and do the best we can with what we've got."
Jerome Solomon's e-mail address is email@example.com