When the Eagles opened training camp at Lehigh University four months ago and Winston Justice lined up as the starting right tackle because of Shawn Andrews' aching back, it was perceived as one of those uh-oh moments.

When the season opener loomed six weeks later and Andrews' back pain resurfaced, speculation immediately arose that the Eagles would bring back Jon Runyan. The iron-man right tackle had started every game for the franchise in this decade (and signed with San Diego last night).

Instead, the Eagles gave Justice the chance he had waited so long for, and yesterday the former second-round draft pick literally cashed in by signing a four-year contract extension that is worth between $18 and $20 million, depending on whether he reaches certain incentives. The deal includes a $6 million signing bonus, a league source said.

Justice, who is in the final year of his rookie contract, admitted he couldn't see such a deal coming when he checked into his dorm room at Lehigh.

"No, and I don't think anyone could, really," he said during a news conference at the NovaCare Complex. "I think I've come a long way. One of the things that my offensive line coach [Juan Castillo] always told me was that hard work pays off, and I took that mind-set. Even when things were looking bad, I always believed and had faith that hard work does pay off, and I worked pretty hard and I think it's paying off now."

A team source said the Eagles were negotiating with other players and were hopeful that they could get at least one more extension done. Wide receiver Jason Avant and guard Nick Cole are in the final year of their contracts and are players the Eagles want to retain.

Before this season, Justice was known for only one thing. He was the starting left tackle the night the New York Giants tied an NFL record with 12 sacks of quarterback Donovan McNabb, and much of the blame was pinned on Justice, who was filling in for an injured Tra Thomas.

That was the only start of Justice's career before this season, and his one-game resumé had left him with the label that he couldn't play in the NFL.

"I think every player has his ups and downs, and after that game I was down for a long time," Justice said.

Determined to change the perception, a more mature Justice decided this off-season that he would remain in Philadelphia and work with Castillo.

"I just really wanted to make a change," Justice said. "I really wanted to make a commitment to my work because I really feel that I was put there for a reason. I think that was the biggest difference this year. I really made a dedication to my trade. I had an opportunity to come back and show the coaches I could play and show the fans I could play, and I tried to make the most of that opportunity."

The new contract is proof that he has. It's also proof that the Eagles believe that Justice will be their starting right tackle for a while, and he's proved he can handle the job.

Conservative estimates were that Justice allowed four sacks during his nightmarish 2007 start against the Giants. In 10 starts this season, he has allowed just three sacks, according to the Stats Web site.

Justice is one of 19 right tackles in the league to start all 10 games this season. Only nine of those 19 have allowed three sacks or fewer. He has also been penalized three times. Only 10 of the 19 right tackles who have started all 10 games have been penalized three times or fewer.

It remains to be seen what Justice's emergence means for Shawn Andrews' future in Philadelphia.

"It's really irrelevant right now," general manager Tom Heckert said when asked if the Eagles could formulate plans that include Andrews, who is spending his second straight season rehabilitating a surgically repaired back in Southern California.

Andrews is signed through 2014, but if he has a future with the Eagles, it could be back at right guard, where he is a two-time Pro Bowler. That position was supposed to be filled by his brother Stacy this season, but he has been replaced by Cole as the starter.

None of that should concern Winston Justice, because he's the right tackle with the new four-year contract that nobody could have envisioned four months ago.

Contact staff writer Bob Brookover at 215-854-2577 or bbrookover@phillynews.com.