The world's top player, practising with Diego Maradona's Argentina for the finals in South Africa that kick off on June 11, fell and suffered a minor scrape on his right knee at the team's training base outside Buenos Aires.
"We all got a fright," said Maradona with a grin in an interview with
Canal 13 television station later on Friday.
"I didn't see it, my back was turned. He and Masche (Javier Mascherano) clashed knees and then I saw that Messi had stopped. But it's nothing, he put ice on it and if he wants to play on Monday (against Canada) he'll be on the pitch."
Team doctor Donato Villani said on the Argentine Football Association website: "It was just a scrape."
Messi, Argentina's big hope after a brilliant season at Barcelona including top scoring in Spain's La Liga with 34 goals, got up and walked from the training pitch after the accident.
Argentina, who face Nigeria, South Korea and Greece in Group B, began their countdown on Thursday and are preparing for a warm-up on Monday against Canada.
The team's farewell match at the River Plate stadium will double as part of the country's bicentennial independence celebrations.
