Brazilian Casemiro joined Argentine star Lionel Messi to defend Inter Miami colors as announced Wednesday, but the Major League Soccer (MLS) immediately announced it is investigating allegations related to the club violating negotiation rules in this deal. Casemiro, who played 91 international matches for Brazil and won the Champions League five times with Real Madrid, became a free agent after Manchester United decided not to renew his contract following a mixed four-year period with the Premier League giant. The 34-year-old midfielder chose to join Messi and fellow Argentine Rodrigo De Paul at Inter Miami, a club co-owned by Englishman David Beckham.

Jorge Mas, managing owner of Inter Miami, said: 'Casemiro's arrival reflects the vision and ambition that define Inter Miami. We are never complacent. We always seek to grow, improve, and raise our standards every season.' He added: 'We have built a global club with a vision to become not only the best club in the United States, but also a global reference.'

But moments after the announcement, the MLS said in a statement: 'We are reviewing allegations regarding a violation of negotiation rules by Inter Miami.' The investigation relates to 'discovery rights' in the American league, which clubs must obtain before beginning negotiations to sign certain prominent players. The LA Galaxy held the discovery rights for Casemiro, and it is understood that they will receive compensation from Inter Miami. The statement said: 'The league is gathering all relevant information and will refrain from further comment until the review is complete.'