Everything we know about Trevor Bauer's grievance hearing against MLB play What's next for Trevor Bauer after 324-game suspension? (2:12) Alden Gonzalez breaks down everything you need to know about Trevor Bauer's 324-game suspension. (2:12) 7:00 AM ET Alden GonzalezESPN Staff Writer Close ESPN baseball reporter. Covered the L.A. Rams for ESPN from 2016 to 2018 and the L.A. Angels for MLB.com from 2012 to 2016. It was 325 days ago that Major League Baseball first placed Trevor Bauer on administrative leave, the start of a process that has become more prolonged and more complex than either side could have anticipated. Bauer, at that point a reigning Cy Young Award winner and one of the sport's highest-paid players, faced allegations from a San Diego woman who accused the Los Angeles Dodgers pitcher of sexual assault, declarations that Bauer has vehemently refuted. He emerged from two legal battles relatively unscathed, first when an L.A. judge denied the woman's request for a restraining order and then when the L.A. County District Attorney's Office declined to file criminal charges . But MLB conducted its own investigation into that incident and eventually others, reportedly interviewing at least two other women who made similar allegations to The Washington Post. And on April 29, three weeks into the 2022 season, MLB commissioner Rob Manfred acted with unmistakable force, suspending Bauer for 324 games , the equivalent of two full seasons. It was twice longer than any player had been suspended since MLB and the MLB Players' Association launched their joint domestic violence, sexual assault and child abuse policy in August of 2015. Editor's Picks Will Trevor Bauer ever pitch in MLB again? What's next after unprecedented 324-game ban 23d Alden Gonzalez and Jeff Passan Source: Bauer's hearing vs. MLB to begin May 23 4d Alden Gonzalez 1 Related Now the validity of that ruling is largely in the hands of one man. His name is Martin Scheinman, and he is the arbitrator currently on retainer by MLB and the MLBPA. Beginning Monday -- and potentially lasting for several weeks thereafter -- Scheinman will serve as the panel chair for Bauer's grievance hearing against MLB , ultimately deciding whether his suspension will be upheld, reduced or thrown out. It's a process rooted in the 1970s, but one that has handled mostly suspensions around performance-enhancing drugs in recent years -- Bauer is the first among the 16 players suspended under the domestic violence policy to challenge his suspension . "The drug stuff is a scientific finding," a longtime arbitrator who used to preside over MLB grievance hearings told ESPN. "It's objectively verified. This is a very different circumstance." How the process works The collective bargaining agreement describes grievance hearings as "a cooperative endeavor to review and secure the facts which will enable the Arbitration Panel to make just decisions." Scheinman will serve as the head of a three-person arbitration panel that also consists of an MLB representative and an MLBPA representative and is expected to issue the tiebreaking ruling. The decision of that panel shall be "full, final and complete," according to the previous CBA. (The new CBA has yet to be published, but the language around grievance hearings is unchanged, according to a source.) Grievance hearings often take the form of a trial, with witnesses called for testimony and cross-examination. Instead of a courtroom, however, those hearings usually take place in meeting rooms -- and in this case, might take place over video conference. The full list of witnesses for and against Bauer will remain confidential, like the rest of this process, but one of the women who spoke to The Post has said she is willing to testify. (MLB has not and, under its domestic violence policy, is not allowed to publicly release the findings of its investigation. It is unknown how many women the league has spoken with or what allegations were made.) These are "parties with unlimited resources, highly demanding clients on both sides, so this is full-blown litigation," said the former arbitrator, who preferred not to be identified given the topic's sensitivities. "It will be like federal court litigation." Scheinman is the fourth arbitrator since 2000 to be retained by MLB and the MLBPA, both of which have the power to replace arbitrators at will. First it was Shyam Das, who was fired by MLB after overturning Ryan Braun's steroid suspension over a chain-of-custody issue in 2012, ending a 13-year run. Then it was Fredric Horowitz, who was fired by the MLBPA after ruling against infielder/outfielder Charlie Culberson in an injury assignment case in 2016. Then it was Mark Irvings, who was fired by MLB shortly after ruling in its favor in Kris Bryant 's hearing over alleged service-time manipulation in 2020. Scheinman, who declined to comment on the case, was retained in 2020. A full-time arbitrator and mediator since 1979, he has resolved more than 20,000 disputes, according to his company's website. The website states that his practice, Scheinman Arbitration & Mediation Services, has "mediated dozens of the highest-profile cases involving allegations of sexual harassment" but says nothing about domestic violence. Scheinman's schedule is so demanding that two assistants at his firm are solely responsible for managing it. He presides over hearings five days a week and is retained by a multitude of companies, a reality that could extend Bauer's grievance hearing deep into the summer, according to sources familiar with the process. In the past, MLB typically has blocked out two days a month on its arbitrator's schedule nearly a year in advance. But additional openings can often be created in an effort to expedite the process -- particularly in a case like this, in which a player suspended under the domestic violence policy must remain on the restricted list (unlike those suspended for PEDs, who can play while the grievance process takes place). Why this hearing is different The most notable grievance hearings of recent years -- Braun's positive test, Bryant's call-up to the major leagues, Alex Rodriguez's lengthy suspension for violating MLB's drug policy -- were grounded largely in verifiable facts. Bauer's case will navigate the subjectivity of alleged assault within the scope of consensual rough sex. MLB must prove just cause, which, according to the former arbitrator, can be an "indefinable concept" in this scenario. "I actually think it's about the hardest ask there is, and the reason for that is because it entirely turns on credibility, it entirely turns on the arbitrator making the determination that one party or the other party is telling the truth," said Leigh Goodmark, the Marjorie Cook Professor of Law at the University of Maryland and a prominent voice in the field of gender violence. "In a case like this one, at the point at which the descriptions of what happened diverge from each other, they diverge so completely that the arbiter is gonna have to go all-in on one of these stories or the other." On Feb 8, moments after the L.A. County District Attorney's Office announced he would not be criminally charged, Bauer uploaded a seven-minute video to YouTube titled "The Truth," in which he denied the San Diego woman's assault allegations, concluding: "I never assaulted her in any way, at any time, and while we did have consensual rough sex, the disturbing acts and conduct that she described simply did not occur." Bauer was just as forceful in his rebuttal of an Aug. 14, 2021, Washington Post story about an Ohio woman who sought a temporary restraining order against him in June 2020, alleging that he choked her and punched her on multiple occasions. And in his rebuttal of a Post story from April 29 of this year about another Ohio woman who alleged he choked her unconscious multiple times during a years-long relationship that began in 2013. In both instances, Bauer used his social media accounts to firmly deny wrongdoing. Bauer has filed defamation lawsuits against two media companies, Deadspin and The Athletic, and has also filed suit against the San Diego woman, whom ESPN has chosen not to name. Sources close to Bauer point to his tense history with Manfred -- which includes stark criticism of Manfred's handling of the Houston Astros ' sign-stealing scandal, policing of foreign substances on baseballs and efforts to market the game to a younger audience, among other subjects -- as a potential reason why his suspension is so long in comparison to others. Six of the 15 players previously suspended under the league's domestic violence policy were punished despite not being arrested or criminally charged, as was the case with Bauer. Those suspensions ranged from 30 games (Aroldis Chapman and Starlin Castro) to 81 (Domingo German ) to 162 (Sam Dyson). But Bauer is the first, among all players suspended under the policy, to have multiple accusers go public -- an example of why MLB allowed itself the leeway to punish players for "just cause," rather than rely on the legal system. There is no obligation to adhere to the Federal Rules of Evidence during a grievance hearing, giving the arbitrator more leeway to review material he or she might deem necessary. But MLB's burden of proof will still be difficult, according to a source familiar with the process. "It's very challenging to be a fact-finder in a case where there is any allegation involving sexual misconduct," said Jill Engle, who serves as the associate dean for academic affairs at Penn State University's law school and specializes in family law and domestic violence. "It's hard for judges, it's hard for juries, it's hard for arbitrators, it's hard for any fact-finder, whether it's in the civil or criminal context, and whether it's private or public, big or small, because we're dealing with human beings and human behavior that happens in the most intimate, private setting when there's almost never a witness." What's at stake Bauer signed a three-year, $102 million contract with the Dodgers in February 2021, on the heels of winning the National League Cy Young Award as a member of the Cincinnati Reds during the COVID-19-shortened 2020 season. But he was placed on administrative leave midway through his first season and hasn't pitched since. Because Bauer is appealing the suspension, his time on administrative leave didn't count toward time served. His suspension began on April 29 and extends into the 19th game of the 2024 season, beyond his contract with the Dodgers. Bauer was paid his full $38 million salary in 2021 but stands to lose roughly $60 million if his suspension is upheld. The Dodgers have abstained from commenting on Bauer while the process has played out, but the expectation from people with direct knowledge of the team's thinking is that if his suspension is shortened, the Dodgers would release him at its end and absorb whatever money remains on his contract. The question then would be which team, if any, would be willing to take a chance on Bauer.