Embattled New York Yankees slugger Alex Rodriguez asked a federal judge on Monday to throw out an arbitrator's decision suspending him for the 2014 baseball season for doping, escalating a battle with Major League Baseball that shows no signs of abating.

In the petition, filed by Rodriguez's attorneys at the U.S. District Court in Manhattan, they said arbitrator Fredric Horowitz exhibited "blatant partiality" toward MLB.

Rodriguez also said in his petition that the league's initial 211-game ban was impermissibly long under the terms of baseball's labor agreement and he accused MLB officials of leaking details about the case to the media.

Monday's lawsuit included a copy of Horowitz's decision, which had not previously been made public, giving the first glimpse of a proceeding that had taken place behind closed doors.

Horowitz ruled on Saturday that Rodriguez, baseball's highest paid player, would miss all 162 regular season games this year as well as the playoffs.

The ban, which was reduced from 211 games, is the longest ever in baseball for the use of performance-enhancing drugs and will cost Rodriguez $25 million in salary.

The 38-year-old third baseman, popularly known as A-Rod, is currently fifth on baseball's all-time home run list with 654 and was once widely expected to challenge Barry Bonds' record of 762 home runs. Bonds was also repeatedly linked to doping.

Monday's complaint may represent a long-shot bid, given that MLB and the players' union agreed on the arbitration process. Federal judges typically afford independent arbitrators great deference under such circumstances.

The filing was expected after A-Rod vowed to take his fight to federal court, claiming the arbitration process was based on unreliable evidence and inconsistent with baseball's collective bargaining agreement.

MLB Commissioner Bud Selig handed down the suspension last August after Rodriguez was implicated in an investigation into a now-defunct Miami anti-aging clinic, Biogenesis, that is accused of distributing performance-enhancing drugs to athletes.

Thirteen other players were suspended for their alleged ties to the Biogenesis clinic, with 12 of them agreeing to 50-game suspensions, and Milwaukee Brewers' slugger Ryan Braun - a former National League most valuable player - accepting a 65-game ban.

Baseball's rules call for a 50-game ban for first-time offenders, but MLB lengthened Rodriguez's suspension for allegedly using drugs over several years and interfering with the investigation.

In appealing the suspension, Rodriguez said he did not use any illicit drugs supplied by Biogenesis and claimed he had been made a scapegoat.

He also filed a previous lawsuit against MLB in October, asserting that its investigators had acted unethically in the Biogenesis probe, including intimidating witnesses and buying evidence. That case is separate from the petition filed on Monday.

The Yankees said in a statement on Saturday that they accepted Horowitz's decision. Under Rodriguez's contract, the team will still owe him $61 million for three more seasons after this year as well as potential bonus payments when he reaches certain home run milestones.

Rodriguez has previously acknowledged using performance-enhancing drugs more than a decade ago when he was a member of the Texas Rangers, but has denied doing so since then.

Long considered one of baseball's top players, Rodriguez has seen his production diminish in recent seasons after a series of injuries sapped his effectiveness.

(Reporting by Joseph Ax; editing by James Dalgleish, G Crosse)