Diego Maradona called Juan Roman Riquelme a "traitor" on Wednesday for leaving Boca Juniors, renewing a feud that has gone on for years between the two.
Maradona used the term in a radio interview, which is sure to anger Riquelme.
"If one wants to fight with Maradona, that's not important to me," Maradona said on Radio Metro. "But what you can't do is be a traitor to the fans at Boca."
Riquelme, a former Barcelona and Villarreal playmaker, shocked Boca fans by announcing he was leaving immediately after the club lost to Corinthians earlier this month in the final of the Copa Libertadores — the top club championship in Latin America.
Riquelme said he was "empty" and had nothing left to give to the club, with reports immediately suggesting he might move to another Argentine team, or to a club in China or in the Middle East.
"You can't be empty just after losing the final of the Copa Libertadores," Maradona said. "If you're empty, then fill up the tank."
Maradona gained his early fame at Boca Juniors and, like Riquelme, was a fan favourite.
When he was coaching Argentina's national team, Maradona often overlooked Riquelme, declining to call him up for the 2010 World Cup.
Riquelme played for Argentina at the 2006 World Cup, leading the team to the quarterfinals under coach Jose Pekerman.