NEW YORK -- The Players Association has filed a grievance against Major League Baseball with the intent of overturning the 15-day suspension meted out last week to Kansas City Royals outfielder Jose Guillen, a union spokesman confirmed on Tuesday.

Guillen and Jay Gibbons of the Orioles were both suspended last Thursday by Commissioner Bud Selig after investigations into their alleged use of performance-enhancing drugs during the period from 2003-05.

Shyam Das, baseball's special arbitrator, is expected to hear the grievance sometime early next year, but a hearing has not been scheduled.

"It's been agreed that the matter needs to be resolved prior to Opening Day," Michael Weiner, the union's general counsel, told the Associated Press.

Both players were interviewed by Rob Manfred, MLB's vice president of labor relations and human resources, after press reports revealed that they had received drugs from Florida clinics being investigated as part of a far-reaching probe by the Albany, N.Y., district attorney.

MLB's drug policy in 2004 called for a player being anonymously placed into a clinical tract for a first positive test and suspended for 15 days for a second positive test. The penalties now are a 50-game suspension for a first offense, 100 games for a second and a lifetime ban, with the possibility of reinstatement after two years, for a third.

Gibbons and Guillen are the first active players to be suspended for drug use without failing a urine test since a drug policy was first collectively bargained into the 2002 Basic Agreement. The suspensions are set to be served at the start of the 2008 season.

Two years ago, then-Diamondbacks reliever Jason Grimsley was suspended for 50 games after his name surfaced in a federal probe as having procured and taken human growth hormone (HGH). Grimsley, who asked for and was given his release at the time, subsequently retired. The union decided there was no reason to grieve Grimsley's suspension because it was never served.

Guillen, a free-agent outfielder who recently signed a three-year, $36 million contract with the Royals, apparently asked the union to pursue the matter.

Four players -- Mets pitcher Scott Schoeneweis, Angels outfielder Gary Matthews Jr., Blue Jays third baseman Troy Glaus and Cardinals outfielder Rick Ankiel -- were cleared of any potential discipline last week by Selig after MLB determined that there was insufficient evidence of a violation in those four cases.

Two investigations, involving Rangers outfielder Jerry Hairston Jr. and Indians pitcher Paul Byrd, remain open.

Manfred and/or other MLB lawyers have met with all the players, who were also involved in the Albany investigation.

Guillen and two former Major League players -- third baseman Matt Williams and pitcher Ismael Valdez -- were reported on Nov. 6 to have bought performance-enhancing drugs from a Florida clinic.

The purchases mostly came prior to the beginning of drug testing for steroids in 2003. HGH, which remains unreliably detectable through a urine test, wasn't put on the list of banned substances until 2005.

Records said that Guillen purchased $19,000 worth of drugs from the Palm Beach Rejuvenation Center, which, along with other anti-aging clinics and online pharmacies in Florida and Alabama, was targeted for illegal sales of drugs, including steroids and HGH. It was raided by Florida law enforcement agencies on Feb. 27.

Guillen purchased the drugs between May 2002 and June 2005, during which he played for Arizona, Cincinnati, Oakland, the Angels and Washington. Williams was playing for the Diamondbacks in 2002 when he purchased $11,600 worth of HGH, steroids and other drugs. Valdez bought $11,300 worth of performance-enhancing drugs in 2002 after he was traded from the Rangers to the Mariners.

Some of the prescriptions were written by a Florida dentist whose license has since been suspended.