Major League Baseball is grappling with another significant sports betting integrity issue after placing Emmanuel Clase, one of the league's most dominant

Major League Baseball is grappling with another significant sports betting integrity issue after placing Emmanuel Clase, one of the league’s most dominant relief pitchers, on paid leave pending an investigation. The Cleveland Guardians closer is now the second pitcher from the team to be investigated this summer, amplifying concerns about the vulnerability of the sport to betting-related corruption.
In a brief statement on Monday, MLB confirmed that Clase had been placed on leave “per an agreement with the MLB Players Association” while the investigation proceeds. This follows an ongoing probe into his teammate, starting pitcher Luis Ortiz, creating a deeply troubling situation for both the club and the league as a whole. Clase is arguably the most prominent active player to be publicly investigated for betting since the repeal of PASPA in 2018.
The investigations have cast a harsh spotlight on the integrity of “microbetting” markets. These are granular, in-play wagers that allow customers to bet on the outcome of discrete events within a game, such as the result of the next pitch. While popular with consumers, these markets are considered high-risk by integrity experts because they can be manipulated by a single player’s actions without affecting the final outcome of the game.
The probe into Luis Ortiz reportedly centres on suspicious betting patterns detected around specific pitches he threw in two games in June. This aligns with public concerns previously voiced by MLB Commissioner Rob Manfred, who has expressed his disdain for such wagers. “Certain types of bets strike me as unnecessary and particularly vulnerable - things where it’s one single act and doesn’t affect the [game] outcome necessarily,” Manfred has stated.
The situation in Cleveland is not an isolated incident but part of a disturbing trend across professional US sports. Earlier this year, the NBA issued a lifetime ban to player Jontay Porter after an investigation found he conspired with bettors to fix his own performance for wagering purposes.
MLB has also taken strong action recently, permanently banning San Diego Padres infielder Tucupita Marcano last June for betting on games involving his own team. These cases highlight the systemic challenges leagues are facing in protecting the integrity of their competitions in the era of legal, widespread sports betting.
The proliferation of these scandals is now leading to calls for a more drastic regulatory response. Industry insiders speculate that MLB may follow the lead of the NCAA, which successfully lobbied US states to prohibit proposition bets on college athletes following a series of harassment incidents. With its slow pace and distinct plays, baseball is considered particularly susceptible to microbetting manipulation.
This momentum is already visible at the state level. A New Jersey assemblyman recently introduced a bill seeking to prohibit all microbets at licensed sportsbooks across the state, citing the need to safeguard sporting integrity. As leagues and legislators confront the mounting evidence of these markets’ vulnerabilities, the future of granular in-play betting in the US appears increasingly uncertain
