Anquan Boldin is in the process of firing agent Drew Rosenhaus, the NFL Players Association said yesterday.

The Arizona wide receiver, embroiled in a long contract dispute, informed the NFLPA in a letter that he intended to replace the agent.

The players' union said it received the letter on Friday, so with the required five-day waiting period, Boldin can sign with a new agent tomorrow.

Boldin, who has two years left on his contract with the Cardinals, is upset with the team's management over what he claims was a failed promise for a new deal last summer. He has asked for a trade. The Cardinals took offers, but on draft day they said no team had proposed a deal that could be seriously considered.

The three-time Pro Bowl receiver has not participated in any of the Cardinals' voluntary workouts for the last two weeks.

The Cardinals had no comment.

NFL will appeal ruling. The NFL filed notice that it will appeal a federal judge's ruling in the case of two Minnesota Vikings players facing suspensions for positive drug tests.

Last week in Minneapolis, U.S. District Judge Paul Magnuson threw out most of the claims by Vikings defensive tackles Kevin Williams and Pat Williams.

But Magnuson sent the Williamses' two remaining claims to a state court.

The NFL has asked the Eighth Circuit Court of Appeals to review whether Magnuson misapplied federal law when he did not dismiss those two claims outright.

Healthy research. NFL-sponsored research showed that, compared with other men their age, NFL players were more than twice as likely to have high blood pressure - 14 percent versus 6 percent for non-players.

The study appears in today's issue of the Journal of the American Medical Association.

Noteworthy. Dallas Cowboys owner Jerry Jones said former Pro Bowl defensive end Greg Ellis would be traded or released. . . . Quarterback Tom Brady practiced with the New England Patriots for the first time since suffering a knee injury in last season's opener. . . . The Cleveland Browns signed recently released cornerback Rod Hood, a former Eagle who started for Arizona in last season's Super Bowl. . . . The Miami Dolphins gave a two-year extension worth $16.2 million to cornerback Will Allen, the Florida Sun Sentinel reported.