Ronaldo Nazario has admitted that Roberto Ayala was the defender who gave him the most trouble during his career.
The pair were rivals on the international stage due to their allegiances to Brazil and Argentina respectively, but they also crossed paths in both Italy and Spain at club level.
"Roberto Ayala was probably the defender who hit me the most in my career," Ronaldo explained in an interview with La Gazzetta dello Sport.
"Every time I faced him, he always threatened me and played to the limit.
"I just tried to defend myself."