It's a big day for baseball-and-steroids lawsuits, as Deadpsin notes. Albert Pujols has sued Jack Clark for deafamation in state court in Missouri, over Clark's statements on a radio program in August that Pujols used steroids. Clark's statements were based on an alleged conversation with Pujols' former trainer.
I have argued before that we should not infer that someone used steroids if they fail to sue over accusations of doping; the legal standard of actual malice is so high that the player may well lose, even if he didn't used PEDs. Pujols' complaint works to overcome that; it is loaded with allegations to show actual malice--including that Clark was trying to drum-up ratings for a new radio program, that the trainer disavowed ever having these conversations with Clark, and that Clark supported Pujols' charitable efforts (something he would not have done had he believed Pujols was cheating).
The Complaint is angry (perhaps too much--it engages in the kind of redundant hyperbole that I tell students often undermines credibility). But Pujols seems determined to use litigation to try to establish that he does not dope.