The 24-year-old is a much sought-after talent, with teams across Europe plotting summer raids for his services.
Gremio vice-president Odorico Roman believes the talented forward would not look out of place in any of those divisions, with Luan considered to be the hottest prospect in Brazil at present.
“There are many teams interested in Luan, from all over Europe,” Roman told FCInterNews.
“There’s nothing concrete though, so I can’t name the clubs and it wouldn’t be fair to publicly reveal their intentions.
“Luan is a very strong player and a rare talent. He was a protagonist for the Brazil team who were Olympic champions.
“He’s not appreciated in Europe like Gabigol or Gabriel Jesus, but in my opinion he’s better than both.
“He’s 24, so that augments the risk of not adapting the old continent where I don’t think they play the same kind of football, but I repeat, he has great qualities.
“I don’t think his value can be far away from Gabigol or Gabriel Jesus. He played more than them in the Olympics, and he’s currently the best striker in Brazil.
“For us the ideal would be sell him now but keep him until the end of the season in December.”
Luan made his senior international debut for Brazil in January, having previously formed part of their gold medal-winning squad at the 2016 Olympic Games in Rio de Janeiro.