Tyson Clabo and Renardo Foster began training camp with little hope of winning a starting job with the Atlanta Falcons.

Five weeks later, the two offensive linemen not only are starters, but they face a seemingly impossible challenge against the New York Giants on Monday night.

"It’s a big opportunity," Clabo said. "Obviously, those guys are second to none in a lot of people’s eyes, so we’ll see how I hold up."

Clabo was an undrafted rookie out of Wake Forest when he made Denver’s practice squad in 2004. After working in the same capacity for the Falcons the following year, Clabo started 10 games last season, filling in for guards Kynan Forney and Matt Lehr.

Now Clabo is filling in again, this time for Todd Weiner, who is expected to miss two to six weeks following knee surgery Wednesday.

Playing four quarters at right tackle would be hard enough, but trying to hold back his primary opponent, legendary New York left end Michael Strahan, only makes the task more daunting.

Strahan ranks seventh on the NFL’s career list with a team-record 133« sacks. He moved past Pro Football Hall of Fame inductee and former Giants star linebacker Lawrence Taylor in a 16-3 win over Philadelphia on Sept. 30.

Clabo must also contend with Strahan’s backup, Justin Tuck, who has 4« sacks.

"They can really, really get after the passer, and what makes them elite, in my opinion, is they can also stop the run," Clabo said. "That’s a tough combination when you’ve got guys who can play both so well."

Considering that Falcons quarterback Joey Harrington has been sacked 17 times — second-most in the NFL — Atlanta (1-4) has little room for error against New York (3-2).

Foster made Atlanta’s final cut as an undrafted rookie. The former Louisville standout faces one league’s top pass rushers in right end Osi Umenyiora.

Tied atop the NFL with seven sacks, Umenyiora set a Giants single-game record with six against the Eagles. Umenyiora leads New York over the last four years with 34« sacks.

Foster is filling in for Wayne Gandy, a 14-year veteran left tackle whose season ended with a knee injury in last week’s loss at Tennessee.

"It’s a big challenge, but I’ll be ready," Foster said. "The thing about them is that they have the experience. With a whole week of preparation, I’m watching as much film as possible and learn their techniques also."

The defensive line could receive a big boost if tackles Rod Coleman and Jonathan Babineaux could return from knee injuries.

Coleman, trying to make his first appearance of the season, was held out of practice Friday after having limited participation Thursday. Babineaux had limited participation both days.

Babineaux, who began the season as the fill-in starter for Coleman, hurt his knee Sept. 23 against Carolina.

Backup quarterback Byron Leftwich, who hurt his ankle Thursday but called the injury minor, also was held out Friday.

Also, defensive tackle Grady Jackson (back) did not practice Friday.

The team listed Coleman, Babineaux and Leftwich as questionable for the game. Jackson is listed as probable. Linebacker Keith Brooking, who had limited participation Friday, also is questionable with a hamstring injury.

Last year against the Giants, Warrick Dunn’s 90-yard touchdown run at the Georgia Dome gave the Falcons a 14-3 lead early in the third quarter. New York then scored the next 24 points. Falcons quarterback Michael Vick was sacked seven times for minus-48 yards.

Six years ago at the Dome, New York held Atlanta to 13 yards rushing on 14 carries, an all-time franchise low for the Falcons. Jamal Anderson, one year removed from reconstructive knee surgery, ran 12 times for 12 yards.

New York, which won the matchup 13-6, advanced to the Super Bowl.

Atlanta finished 4-12.