Jorge Messi tells Barcelona-based La Vanguardia newspaper "the plan is to stay here, but since people read between the lines they exaggerate."
He says "Leo is happy, but if one day the club says, 'We have an offer for you, we want to sell you,' well, we would have to study it."
Lionel Messi said Tuesday that he would like to stay at Barcelona but "sometimes not everything happens the way you want."
The 27-year-old Messi, Barcelona's all-time leading scorer, is under contract until 2018.
Last May, Barcelona said it had improved the terms of his contract.