The Cardinals have lost four straight and the lofty expectations the team had before the season have been shot full of holes. But Darnell Dockett wants to stick around.

“Even though we are 1-4, I still believe in the program, long term. I feel we are getting better,” the defensive tackle said. “And I feel this will be a playoff team.”

So Dockett committed the bulk of his career to the Cards Friday, when he signed a five-year contract extension through the 2011 season. It wasn’t exactly a chore, given that the deal will hand him $7 million in bonuses over the next six months and could potentially pay Dockett almost $22.5 million.

But it was still a barometer that players haven’t bailed on the struggling franchise.

“If you approach players early (on contract extensions) they are always receptive,” vice president of football operations Rod Graves said. “(But) players’ attitudes now are also better about wanting to stay here.”

The Cardinals had more than $10 million in cap space available, but that will be eaten up by an immediate $3.5 million bonus. Dockett will also receive a $3.5 million roster bonus early next year.

Dockett’s 2006 salary of $425,000 doesn’t change. His salaries in the new pact will be $510,000 in 2007, $3.25 million in 2008, $3.5 million in 2009, $3.75 million in 2010 and $4 million in 2011. His salary cap charge in 2007 will only be about $1.2 million.

“A lot of people talk about the Cardinals, ‘The Cardinals are cheap, they don’t want to spend money,’ ” Dockett said. “I don’t think this is that. I am a true believer. Hopefully, they keep the guys around here that want to win and they get more guys in here that want to win.”

Graves said the team will continue to look at other current players’ contracts that they might extend during the rest of the regular season. He also said the team is evaluating who is part of the core group the Cards want to retain and who won’t be back next season.

Graves wouldn’t be specific, but there are a handful of players that the franchise will be closely monitoring.

Linebackers Karlos Dansby, who is signed through 2007, and Gerald Hayes, who will be an unrestricted free agent, are two potential targets. But in Dansby’s case, an injury-filled training camp has stopped that talk and neither player is currently in negotiations with the team.

One player who likely won’t get en extension is tackle Leonard Davis. Davis, an unrestricted free agent at the end of the season who is making $9.2 million, is on the trading block and almost certainly will hit the open market in March. The Cardinals felt strongly about keeping Dockett.

In five games this season, Dockett has 21 tackles, a sack and a fumble recovery. He becomes the latest in a string of contract extensions over the past few years — along with safety Adrian Wilson, receiver Anquan Boldin and kicker Neil Rackers. The Cards also matched an offer sheet to restricted free agent guard Reggie Wells.

Dockett was frustrated on draft day when he slipped to the third round. He said the contract validates his belief he was undervalued.

“I look back at all the guys who went in front of me and 80 percent of them ain’t doing nothing,” Dockett said.

Coach Dennis Green said Dockett’s play had been solid the past two seasons but that Dockett has played his best this season.

With the Bears visiting Arizona Monday night, Dockett acknowledged a little irritation about hearing about the Bears’ Tommie Harris, a fellow defensive tackle and friend of Dockett’s. Harris was drafted in the same year as Dockett, but in the first round.

“I take it on as a challenge this whole week,” Dockett said. “I know they’re going to talk about Tommie Harris during the game. My goal is they will be talking about me, too.”