"Physically he is in far worse condition than people think," a source from the Delfos clinic in Barcelona was quoted in ADN.
The newspaper suggests the muscular injury that has kept Ronaldinho out for a month is career-threatening and means he might never again play at the highest level.
Inter have also given up on their interest in the Brazilian, so only Manchester City remain with an offer of £31.5m.
According to ADN and Globoesporte, Ronaldinho underwent the tests in a private clinic without Barca's knowledge.