On Wednesday, a court sentenced Messi and his father, Jorge Horacio Messi, to 21 months in prison.
Barcelona issued a statement to "give all its support to Leo Messi and his father". In Spain, sentences of less than two years for first offences are usually suspended, meaning neither man will likely go to jail. "He fell victim to a faulty fiscal structure which will be changed".
As you may be aware, he's a super striker for the Spanish football clubBarcelona, but the Spanish Government says that between 2007 and 2009, he defrauded them of more than 4 million Euros - or 4.42 million U.S. dollars.
Messi and his father, who are not expected to serve jail time, have confirmed that they will appeal against the decision.
Barcelona quickly expressed their support of Messi following the ruling, saying they believed he and his father were innocent. Messi, five times World Player of the Year and one of the world's highest-earning athletes with an estimated income of $350 million in the past 10 years, plays for Barcelona football club where he is the leading goal scorer of all time.
Messi captained Argentina in the 2016 Copa America but could not help his team avoid a repeat of their 2015 Copa America final defeat after his side were again beaten by Chile.
La Liga President Javier Tebas shocked the world by revealing that FC Barcelona star and world's best player Lionel Messi might opt to move out of the league!
Information from The Associated Press was used in this report.
With Barcelona, in contrast, Messi has won four Champions League titles, three Club World Cup trophies and eight Spanish league titles.