ST. LOUIS -- These days, the St. Louis Rams don't consider John St. Clair such a liability.

The offensive tackle isn't a major concern heading into the opener -- and his NFL debut -- on Sunday at Denver, even if he has to take on three-time Pro Bowler Trevor Pryce.

"He's progressed and each week he's gotten better, and that's what you're hoping for as a coach," offensive line coach Jim Hanifan said. "John has steadily climbed, and we knew from the get-go how mentally tough he was."

The Rams thought enough of St. Clair, a third-round pick in 2000 who has never been active on game day, that they released Ryan Tucker in a salary cap move to make room. But three weeks ago, St. Clair was a huge question mark after struggling in a preseason game against the Chicago Bears when he was burned for one first-half sack and was part of a second-half collapse that led to seven sacks of third-string quarterback Marc Bulger.

Since then, there's been marked improvement.

"It was a bitter pill to swallow and he had the media all over him," Hanifan said. "Like last week, I said to him, 'Hey, they're not going to interview you."'

Early in the preseason, coach Mike Martz said St. Clair was thinking too much and hitting too little. Lately, he's shed some of that finesse.

"It's like a young receiver coming into the game trying to learn the system, and they kind of forget about catching the football," Martz said. "Once they get through all that and settle down, they're fine, and he's got that down."

St. Clair believes he's made big strides.

"You want to be so technically sound, that's always on your mind," St. Clair said. "It's kind of second nature to me now and now I've got to focus on my game."

A big test early

Out of the gate, St. Clair will be severely tested. Pryce was a force at defensive tackle before being switched to end this year, and in Week 2 he'll have to try to slow down the New York Giants' Michael Strahan, who set record with 22 1-2 sacks last year.

"It's a challenge, but if I go out and do my job everything will work out all right," St. Clair said. "This is the NFL. You've got to go against the top guys every week and I'm looking forward to the challenge."

St. Clair insisted he wouldn't rather face a lesser talent in his debut.

"To me, there's no such thing," he said. "You've got to go in every week with the same idea in mind, to play hard and to play your game. I don't worry about who's across from me."

The 295-pound Pryce was a first-round pick in 1997 and has been to the last three Pro Bowls, amassing 32 sacks in that time.

"He's a guy we felt had a chance to be a dominant player either inside or outside," Broncos coach Mike Shanahan said.