Lucas has revealed he will not make a decision on his future until after the Games in London.
Sao Paulo's director of football, Adalberto Baptista, has admitted they may look to extend the 19-year-old's contract as they look to fend off United's interest in the attacker.
"It's possible we change his contract," Baptista told UOL. "He has four more years of contract. We may call him to extend, renegotiate his contract, maybe for 18 more months."