The 19-year-old has impressed for club side Sao Paulo this season and is regarded as one of South America's hottest prospects.
French television station Canal + have now published photographs showing Madrid president Florentino Perez giving the youngster's parents a tour of the Bernaubeu.
However, the midfielder's agent Wagner Ribeiro, who was also on the tour, confirmed that Los Blancos have yet to make an offer.
"I took Lucas's parents to Real Madrid because I have already visited Italy and England with them," Ribeiro told Brazilian newspaper Globoesporte.
"This does not mean Lucas will play for Real or any other team. At the moment, there have been no offers for him."