Corinthians have issued a 'not for sale' warning to clubs interested in signing their Argentinian forward Carlos Tevez.
Chelsea have become the latest team linked with the Brazilian club's star man, who has also interested Real Madrid.
Blues boss Jose Mourinho is thought to have visited Brazil this week to watch Corinthians play against River Plate in the Copa Libertadores - South America's equivalent of the Champions League.
Although Mourinho played down speculation that the 22-year-old international was the player he had expressly travelled to watch, it would be a surprise if no European club attempted to prise Tevez away from Corinthians this summer.
His stock could rise at the World Cup, but Corinthians owner Kia Joorabchian told The Times: 'There's no point naming a price as he's not for sale.
'He's 22 years old, the best player in South American and one of the best players in the world.
'It's not possible. For me he is irreplaceable.'
Tevez was a £10million signing from Boca Juniors 18 months ago, and finished top scorer in the 2004 Olympic Games football event, with eight goals in six matches as Argentina won the gold medal.
Speaking last week, Joorabchian claimed Tevez would only be allowed to leave for a fee in excess of the current world transfer record, which stands at the £46.5million Real Madrid paid Juventus for Zinedine Zidane in 2001.
'I know that after the World Cup in Germany lot of teams will want to buy Tevez, but it does not matter to us,' said Joorabchian.
'Now, we have a project. In four or five years he will be sold.
'Tevez will leave Corinthians if a team pays the contract's release clause, which is between 100 million and 120 million euros (£69million and £83million).
'Maybe he won't leave Corinthians even for that money. I think that he is very happy here.'
Chelsea have confirmed Mourinho attended the match.
Mourinho, however, played down the link to Tevez, telling www.chelseafc.com: 'People can say what they like, but there are 22 players in this match worth watching.
'I go to the game because it is South America's equivalent of the Champions League and it is a great tournament. Now the Premiership is over I can go and enjoy other football without worry.'