PITTSBURGH - Brian Westbrook and the Philadelphia Eagles agreed to a new contract Friday, prompting Westbrook to say he’ll finish his career with the Eagles as the team opened its preseason schedule against the Pittsburgh Steelers.

The deal is worth $21 million over three years, including $13 million guaranteed the next two seasons, a person with knowledge of the contract told The Associated Press.

The person, who spoke on the condition of anonymity because the negotiations were confidential, said the contract could be worth up to $24 million if Westbrook meets certain escalators. The deal also includes three additional years through 2013 at $10 million per season, but those are strictly for structural reasons.

“I wanted to try to get this thing behind me so I could focus more on the season,” Westbrook said at halftime. “I’m glad that (Eagles president) Joe (Banner) worked with my agent very well and they were able to get thing accomplished.

Westbrook, who turns 29 next month, was in the third year of a five-year, $25 million contract he signed in 2005. He was scheduled to earn $3 million this season with a roster bonus of $1.5 million.

Westbrook said he plans to remain with the Eagles for the rest of his career.

The two-time Pro Bowl running back had said he wanted to restructure his contract because he felt underpaid. Westbrook made it clear he wanted to be compensated like one of the best running backs in the NFL.

That’s just how coach Andy Reid described his all-purpose back in a statement announcing the new contract.

“As I’ve said many times, I believe Brian Westbrook is the best running back in football,” Reid said. “He can do it all from that position, whether it’s running, catching the football or blocking.”

Westbrook was supposed to play about 1½ quarters with the rest of the starters against the Steelers, but Reid decided to keep him on the sideline.

That didn’t stop Westbrook from getting grass stains on his uniform, however.

“I was doing a great job of trying to stay clean,” Westbrook said. “My guys, my offensive line, came over and showered me with some grass.”

Banner said the contract is the most complex he has ever seen.

“It’s a complicated deal with extension years and potential voided years and escalators and everything I’ve ever seen in any contract is in this deal,” Banner said referring to the contract’s 52-page addendum.

The organization isn’t known for giving players new deals with so many years remaining on existing contracts, but made an exception for Westbrook. Two-time Pro Bowl cornerback Lito Sheppard wants a new contract, but isn’t likely to get one and Banner refused to discuss his situation when he spoke about Westbrook’s deal just before Friday’s game.

Terrell Owens was kicked off the team in 2005 after he demanded a new contract and then started creating turmoil and drama, but Banner said Westbrook’s negotiating tactics were “positive and professional.”

“We’re talking about a Hall of Fame-caliber player,” Banner said of Westbrook. “This is a premier guy, a leader, a player. He just wants to win so badly, and that is what drove him.”

Unhappy with the progress of contract talks during the offseason, Westbrook recently fired agent Fletcher Smith and hired Todd France to represent him.

“I didn’t want to be negative about it,” Westbrook said of the negotiations.

“When we came to the final numbers, I presented it to Brian and he said, ’Todd, I gave you three goals and you met or exceeded all those goals. How can I not be happy?”’ France said, declining to give specific numbers.

Westbrook led the NFL with a franchise-record 2,104 total yards from scrimmage last season. He became the first Eagles player to rush for more than 1,000 yards in consecutive seasons since Duce Staley in 1998-99, and led all NFL running backs with a team-record 90 receptions.

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A third-round pick out of Villanova in the 2002 draft, the 5-foot-8 Westbrook has 6,768 yards from scrimmage since becoming a full-time starter in 2004, second only to LaDainian Tomlinson of the San Diego Chargers in that time. Westbrook is the only active player with more than 20 touchdowns both rushing and receiving (27 rushing, 23 receiving).

Westbrook is also the NFL’s leading running back in receptions (338), receiving yards (3,121) and touchdown catches since 2003. He was an All-Pro selection last season.