Year in and year out changes are made within NFL organizations and around the league. Front office personnel, coaches, stadiums, players - you name it. The Eagles have been fortunate enough to have some constants that other teams envy.

Take Philadelphia's two, Pro Bowl, bookend offensive tackles for example. Jon Runyan and Tra Thomas have anchored the offensive line for Donovan McNabb since 2000, when Runyan was signed as a free agent from Tennessee.

They have seen their fair share of changes since they entered the league. Bigger player salaries. The Internet. Pocket-sized cell phones. Not to mention, a different type of strategy on offense.

"It's become more of a finesse thing over the years," Runyan said. "Not so much a grind it out, pounding the ball like when I started. You're talking Eddie George is your tailback. That's not a small guy running downhill. And you see everybody moving towards the West Coast type of stuff, getting the ball out. The rules are changing to adapt the game to do that type of stuff and to score more points."

The defensive ends Thomas and Runyan match up against are now more specialized. There used to be one guy on a team that was the pass rusher and that was all he did, according to Runyan. Now there is a fresh guy coming in almost every down.

"Before it was just like the Derrick Thomases and the Bruce Smiths," Thomas said. "Now, everybody is like that. A lot of speed rushers, a lot of guys working hands, throwing hands. There is no more of the straight power rusher or speed rusher. Everybody has a little bit of mix in there game."

Likewise, Runyan have had to make their own adjustments. Runyan is entering his 13th season and Thomas is entering his 11th. They have worked hard throughout the year to keep from "ballooning" out of shape and then dropped pounds when needed.

"As you get older, you are naturally going to get slower," Runyan said. "You get the weight off so hopefully your speed stays about the same."

The coaching staff really does appreciate and notice what both Thomas and Runyan have done over the years.

"They have great experience and are both terrific players," offensive coordinator Marty Mornhinweg said. "They have both done an excellent job here later in their careers of keeping themselves in terrific physical condition on a consistent basis throughout the year. I think that has added years for both of them. They are both terrific players and we need them both. They both add toughness to the football team."

Runyan and Thomas have started a franchise-record 118 regular season games together as a tackle tandem. Runyan is one of the true ironmen of the game, having started 176 straight regular season contests, which among the top three in the NFL. Thomas ranks fourth in team history in games played by an offensive lineman (150), and seventh overall, having missed just eight games due to injury during his 10-year career.

"That's what they do. They play football," Mornhinweg said. "Both of them have an extremely high pain threshold. It's an uncommonly high pain threshold."

Runyan and Thomas are both elite members of the exclusive "30-Plus Club," enjoying every third morning off. The extra time gives these gladiators of the gridiron some extra time to reflect on all they have accomplished.

"I just look back at it and see how blessed I've been to be with a team this long and to have the career that I've had," Thomas said. "It's been fun. Philadelphia was always the city that I wanted to come and play with from the jump, coming out as a rookie so it was a blessing for me to get picked by them in the first round. To last as long as I have here in the city has been good for me."

Philadelphia is not only his place of business, it's his home.

"I live here during the offseason," he said. "I really enjoy it. I enjoy the people, I enjoy the atmosphere, and the city has really welcomed me and my family."

Both Runyan and Thomas are entering the final year of their contracts, but they are not worried about that. They know they are part of a good football team and they are largely responsible for helping the Eagles be successful.

"I approach it as you go out and take care of stuff on the field and all that stuff (off the field) will take care of itself," Runyan said. "People are going to come knocking down the door for you if you take care of it on the field."