Major League Soccer (MLS) has launched an investigation into Inter Miami CF concerning allegations of tampering related to the signing of Brazilian star Casemiro. The league announced the review on Wednesday, shortly after Inter Miami revealed the midfielder had signed a contract through the end of the current season with an option to extend through June 2029.

"Major League Soccer is reviewing a tampering allegation against Inter Miami CF," the league stated. "The league is gathering all relevant information and will refrain from further comment until the review is complete." MLS also noted that while Inter Miami and the LA Galaxy have reached a settlement regarding discovery priority for Casemiro, the terms will be disclosed after the tampering investigation concludes.

The core of the allegation centers on whether Inter Miami bypassed the MLS “discovery rights” system. This system allows clubs to designate up to six players on a “discovery list,” granting them priority in negotiating contracts with those players. Casemiro was reportedly on the LA Galaxy's discovery list prior to his move to Inter Miami.

Under MLS rules, if a player is on a club's discovery list, only that specific club is permitted to negotiate with the player. Other MLS clubs are prohibited from contacting them. Clubs can acquire discovery rights from another MLS team by offering $50,000 in General Allocation Money in exchange for the right to sign the player. The club holding the discovery rights then has a limited time, typically five days (or three days during the Secondary Transfer Window), to either accept the allocation money and relinquish the signing right or make a genuine offer to the player.

The LA Galaxy reportedly filed the tampering claim against Inter Miami, according to ESPN.