"(Messi) has arrived at the World Cup tired, the damage is already done and it's irreversible," Argentina's fitness coach Fernando Signorini said in an interview with the Catalan magazine Sport.
However, team doctor Donato Villani told a news conference later that all of coach Diego Maradona's squad including Messi were fit for selection for Saturday's Group B opener against Nigeria.
"The 23 players are in optimum condition," Villani said in a brief statement to a packed media room after the team's late afternoon practice.
Signorini, Diego Maradona's personal fitness coach during part of his playing career in Europe, said too much was being expected of the young forward who turns 23 in two weeks' time.
"(The organisers) worry about the doping controls but not if players play 70 matches a year," he said this week after an early morning visit by anti-doping testers to Argentina's University of Pretoria camp.
Fans and media have seen little of the Barcelona ace in the last four weeks although he has been involved in Argentina's practices during the two weeks the squad have been in South Africa.
Having missed Argentina's 5-0 win over Canada in their last warm-up 17 days ago due to a minor knee injury, Messi's last match was in La Liga on May 16. He last played for Argentina against Germany in Munich on March 3.
"He looks really good to me, very keen, dreaming of having a great World Cup," Veron said of Messi.
"But I think that to pile all the responsibility on him for what might happen at the World Cup is not good, that's why there are 23 of us in the squad," he told the news conference.
"I hope he can give all that football he has inside him."
Signorini said Messi "is almost a miracle of genetics because in a single movement he makes six or seven (movements).
"It's his calling to be one of the best (players) in history and surely at the next World Cup he'll be better than in this because to his talent he will add experience."
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