ST. LOUIS -- Albert Pujols sued Jack Clark on Friday over comments on a local radio show accusing the three-time NL MVP of using steroids.

The lawsuit between former Cardinals stars was filed in Circuit Court in St. Louis County, where Pujols lives. It seeks unspecified damages that would be donated to charity, and asks for a determination and declaration that Clark's statements are false.

The petition says Pujols' "character and reputation are impeccable and beyond reproach" and cites his charitable work with the Pujols Family Foundation, while calling Clark "a struggling radio talk show host" who was chasing ratings in the first week his new show was on the air.

Pujols, a nine-time All-Star, played for the Cardinals from 2001-11, then left to sign a $240 million, 10-year contract with the Los Angeles Angels.

"My lawyers have told me that the upcoming legal fight will not be an easy one, and that in cases like this even a liar can sometimes be protected under the law," Pujols said in a statement. "I have never shied away from standing up for the truth, and I believe that the principles at stake are too important to sit back and do nothing."

"I believe we are all accountable for the things we do and say, and it was important for me to stand up for what was right against those who would seek to drag me down to try and build themselves up," he said.

The lawsuit came one day after three-time AL MVP Alex Rodriguez sued Major League Baseball and Commissioner Bud Selig in New York for alleged interference with his current and prospective business deals. Rodriguez has a $275 million, 10-year contract with the New York Yankees, the only baseball deal larger than Pujols' agreement.

Clark played for the Cardinals from 1985-87 and was a four-time All-Star. He made the comments on Aug. 2 on WGNU-AM radio's "The King and the Ripper Show," saying he knew "for a fact" that Pujols used steroids and performance enhancing drugs. He called Pujols "a juicer" and made similar on-air comments three days later.

Clark and his co-host on the program, Kevin Slaten, were fired a week into their tenure, and the station's owner broadcast a lengthy apology and posted similarly contrite statements on its website. The lawsuit does not name the radio station or Slaten as defendants.

Clark, who played 18 seasons for five teams, was the Los Angeles Dodgers' hitting coach from 2001-03. He said on the air that Pujols' personal trainer, Chris Mihlfeld, disclosed that he "shot up" the young player and also offered Clark steroids. Mihlfeld, who also worked for the Dodgers at the time and first met Pujols as his junior college coach, has publicly denied those accusations. The suit references a Mihlfeld statement that Clark's allegations are "simply not true."

The lawsuit says Clark's comments are lies that have damaged Pujols' reputation, causing him humiliation, mental anguish and anxiety. It calls the statements "malicious, reckless and outrageous falsehoods" and said Clark's firing and the show's cancellation don't go far enough.

"Cutting Clark off at the microphone will not undo the harm to Pujols' reputation caused by Clark," the suit says.

On Aug. 10, Clark tweeted: "I completely stand by the story I told 8 days ago about conversations 13 years ago w/ Mihlfeld. He will never admit it."

Clark's attorney, Chet Pleban, said he had not yet seen the lawsuit but Clark "looks forward to having his day in court and having 12 unbiased, impartial people decide the issues."

"And we'll certainly look forward to the discovery process, that will include depositions and the like," he said.

Pleban said Pujols has a "multiplicity of legal hurdles to overcome" to meet the actual malice standard in libel cases brought by public officials -- specifically showing that Clark made a knowingly false statement or with reckless disregard for the truth.

Soon after Clark's comments, Pujols adamantly denied using performance-enhancing drugs, citing his desire to be a role model for his five children and the necessity of being "the athlete to carry the torch and pave the way for other innocent players" by challenging Clark in court.

On Friday, one of the five lawyers he has hired to fight Clark said in a written statement that should Pujols prevail in court, he would donate any monetary damages to charity. Los Angeles attorney Lynda Goldman said Pujols also expects an apology from Clark.