Lionel Messi and Inter Miami will feature in next year's expanded FIFA Club World Cup, FIFA president Gianni Infantino announced on Saturday.
Messi and his team-mates will kick-off the tournament in the opening game at Hard Rock Stadium, home of the NFL's Miami Dolphins, on Sunday, June 15, Infantino added.
The FIFA president was speaking on the field at Inter's Chase Stadium moments after Messi scored a hat-trick as the team broke the MLS regular season points record with a 6-2 win over the New England Revolution.
Miami, who this month won Major League Soccer's Supporters' Shield for the best regular season record, will take the qualification slot designated for the host nation.
"Inter Miami qualifies as the host country representative team on the basis of the club’s outstanding and consistent 34-match campaign that saw them secure the shield with two MLS matches to play," FIFA said in a statement.
The official champions of MLS are determined by the MLS Cup playoffs which begin next week and conclude with the final on December 7.
Miami are the favourites to win the playoffs but the FIFA decision to select the regular season winners ensures the involvement of the Argentine superstar.
The participation of the eight-time Ballon d'Or winner Messi is a much-needed boost to the profile of the new-look tournament, which FIFA hope will capture the imagination of the global television audience as well as fans in the United States ahead of the World Cup in 2026.
The competition could pit Messi against top European club opposition for the first time since he left Paris Saint Germain last year to move to Miami.
The 32-team tournament will feature title winning teams from each of FIFA's continental confederations.
Real Madrid, Manchester City and Bayern Munich are among the 12 European teams who have qualified for the tournament while Argentina's River Plate and Boca Juniors and Brazil's Flamengo are among six South American teams.
FIFA has yet to announce any broadcast deals or sponsorship contracts for the tournament and the competition has faced some opposition within the game.
Players union FIFpro and the European Leagues body filed a joint complaint to the European Commission against FIFA over the introduction of the tournament into the international match calendar.
Opponents of the new tournament have said it adds further congestion to an already crowded schedule and increases the workload of players.
The last version of the Club World Cup featured seven teams in a knockout format and was won by Manchester City who beat Brazil's Fluminense in the final in Saudi Arabia.
FIFA plan to hold the expanded tournament every four years although no host as yet to be chosen for the 2029 edition.