The St. Louis Post-Dispatch reported Tuesday that the news was such a surprise to Coach Mike Martz that he did not find out about it until after his weekly meeting with the media on Monday afternoon.
"Marshall doesn't talk about injuries, as you guys all know," Martz told reporters following his formal gathering. "He doesn't say anything. He's the all-time tough guy."
The paper said Faulk first complained of soreness in the knee in Macomb, Ill., after taking a hit on it during a training-camp practice. He had the knee examined by doctors in Los Angeles and was given a clean bill of health.
Apparently tweaked it on Sunday, when he broke two bones in his left hand after being grounded by Seattle defensive tackle Cedric Woodard in the third quarter.
The knee surgery will not cause Faulk to miss any more time than the four to six weeks it will take to recover from the hand injury. In three games, he had just 116 yards on 42 carries and 66 yards on 12 pass receptions.
Lamar Gordon will start in his absence. He has 14 carries for 72 yards, and he caught seven passes for 51 yards.