"Lions running back Kevin Smith knew it was bad right away. He caught a pass in the flat early in the fourth quarter of Sunday's 48-3 loss to the Ravens, and as he tried to make a cut, his left knee buckled.

"I just remember falling to the ground in extreme pain," Smith said. "It hurt very bad."

Smith was on crutches with a bulky brace on his left knee in the locker room. He said he would undergo testing today in Detroit, but that it didn't "feel real good." Coach Jim Schwartz said the injury looked "significant," his word for long-term.

"There's always going to be things in your way on your way to success," Smith said. "I'm tough enough to fight through whatever's going to happen. I'll find out what's going to happen, and I'll get better real fast. Whatever happens, happens."

The injury is another blow to the Lions, who lost tight end Brandon Pettigrew, the No. 20 overall pick this year, to a torn left ACL on Thanksgiving against Green Bay. Smith, a third-round pick last year, had just drawn praise from the coaches for playing through shoulder problems and starting to hit his stride. He had 21 carries for 69 yards Sunday.

"Kevin's a tough player and was one of the few bright spots in this game and was playing his butt off," Schwartz said. "He wasn't quitting. He was trying to gain yards. He was trying to get first downs. He was trying to get in the end zone as that game was winding down.""