St. Clair's assignment: neutralize Packers' KGB

John St. Clair received a lot of attention in Week 2, when the backup offensive tackle caught Rex Grossman's only touchdown pass of the season -- a 2-yard grab off a trick play against the Chiefs on which he lined up as an extra tight end.

But the 6-foot-5, 315-pound St. Clair hopes to avoid the spotlight tonight against the Packers, when he's expected to start in place of injured left tackle John Tait.

If the focus is on St. Clair, it will probably be because he's struggling to keep the Packers' leading sacker, Kabeer Gbaja-Biamila, away from quarterback Brian Griese.

"KGB" is a sometimes starter, but he's an always pass rusher. The eight-year veteran has 68 career sacks and needs just 1 more to pass Reggie White for first on the Packers' all-time list.

"He's a very quick player," St. Clair said of the 6-foot-4, 247-pound Gbaja-Biamila. "He's not that big of a guy. You've (just) got to play for his speed.

"He's a good player and has been for a long time."

Cullen Jenkins played so well last season that he relegated Gbaja-Biamila to a situational, pass-rushing role, although the arrangement has worked extremely well for the Packers. At 6-foot-2 and 302 pounds, Jenkins is a completely different player, but he had a career-best 6½ sacks last season.

"Both of their defensive ends are good," St. Clair said. "But I'm up for the challenge."

Practicing against the Bears' defense is the best preparation he could have for facing speed pass rushers, according to St. Clair.

Bears defensive ends Mark Anderson and Adewale Ogunleye have combined for 7 sacks this season, and St. Clair practices against both of them since he's the top backup at both tackle positions.

"We're fortunate on this team to have fast guys," he said. "That's what our defense is based on. They can't get any faster than our guys. (I'm) fortunate to go against our guys every day in training camp and practice because that (game) speed is pretty much the same speed we practice against every day."

An eight-year veteran, St. Clair has started 34 NFL games, including two in each of his previous two seasons with the Bears. But this will be his first start of the 2007 season.