FLAGSTAFF, Ariz. -- Larry Fitzgerald has acknowledged that his supreme athletic ability has allowed him to ease off in the effort department from time to time. Not so at this training camp.

Just ask coach Ken Whisenhunt.

"In just the year I've been here with Larry I've seen a lot of improvement," Whisenhunt said. "And that's a hard thing to say, because he's been so productive in the league. But if he continues to work this way, he will really, really be a good receiver as you look back in history."

A new four-year, $40 million contract -- with $30 million guaranteed -- seems to have added to Fitzgerald's motivation.

"I think he's actually more committed to prove that he is worth it," Whisenhunt said. "And that's a good thing. I think he embraces the role of trying to be one of the best receivers in the game."

Fitzgerald is in his fifth season in the NFL, but he's just 24 years old. Already, he has 330 receptions, 4,544 yards receiving and two Pro Bowl appearances. Last year, he led the NFC in receptions (100) and yards receiving (1,409), and tied his career high with 10 touchdowns.

At 6-foot-3, he has a knack for screening out smaller defenders and outleaping them for the ball. And he has among the best hands of any receiver in football. He credits the new Arizona coaching staff of a year ago of helping him with the details of his job.

"I'm still a work in progress," he said. "I'm going to still continue to do the things they teach me to be the dominant receiver I want to be."

Whisenhunt said one play in this camp stood out. It was the end of a tiring session, and the Cardinals called a "go" route for Fitzgerald.

"The thing that kind of jumped off the film was he was hightailing it down the field," the coach said. "Maybe that's something he wouldn't have done consistently in the past, but he's really working on those things now."

The new contract, Fitzgerald said, is just part of the dream that he had when he worked as ballboy for the Minnesota Vikings.

"I'm able to realize that goal for another four years," he said. "I'm ecstatic about that, and I can focus on the basics."

All is not so well for fellow wide receiver Anquan Boldin, himself a two-time Pro Bowl selection. Together, he and Fitzgerald are arguably the best receiving tandem in the NFL. But Boldin lashed out at ownership when camp opened, saying the Cardinals didn't follow through on a new contract they had promised him. Boldin says he will not re-sign with Arizona, although he has three years left on his current deal.

Fitzgerald wishes Boldin well.

"'Q' is my brother, man," Fitzgerald said. "I love 'Q.' A lot of the reasons I'm in the position I'm in now is the help he's been able to provide for me."

World travel is a passion for Fitzgerald. A year ago, he went to New Zealand. This summer, it was on a South American journey to Peru, Brazil, Argentina and Chile.

Back home, he has new responsibilities. His son Devin was born in January.

"Things are just kind of slowing down," he said. "I'm getting kind of older now. Life is slowing down. I'm just really relishing the opportunity to go out there and do what I love to do. Playing ball is a dream come true. Every time I step out on that field, that's what I'm thinking."

Copyright 2008 by The Associated Press