Argentina's coach Diego Maradona, right, blows a whistle as he stands next to forward Lionel Messi during a training session on Tuesday. ((Daniel Garcia/AFP/Getty Images))

All 23 players on Argentina's national squad are in "optimal" physical condition and available to coach Diego Maradona just hours ahead of the start of the World Cup, the team's doctor said Thursday.

The brief statement to reporters by Donato Villani seemed aimed at dismissing rumours of an injury to Lionel Messi, the FIFA world player of the year, and downplay the absence of Carlos Tevez and Gabriel Heinze at a late afternoon practice session on the grounds of the University of Pretoria.

Manchester City's Tevez and Olympique Marseille's Heinze exercised indoors in a gym.

"The 23 players are in optimal physical condition and are not suffering from any kind of illness," Villani said.

Argentina will open its World Cup campaign on Saturday against Nigeria at Ellis Park in Johannesburg.

Media were allowed to witness a few minutes of the end of the practice session, a seemingly carefree game of keep away, with most of the team standing around the middle circle and three players in the middle trying to get possession of the ball.

Later, Messi worked on corner kicks with his masterful left foot at the end of practice, with Maradona standing beside him and talking to his heir apparent for several minutes.

Juan Sebastian Veron, one of the team's most experienced players, said the squad was anxious for the tournament to begin.

"We have a strong desire for match day to arrive," the Estudiantes midfielder said. "The group is well and we can feel this in the daily life together."