Lucas Patinho, 20, was one of the shining lights as Fluminense won the Brasileirão Under-20 crown in December, but finds himself well down the pecking order at the Carioca side.
“We are talking with Sporting and finalising the contract,” Fluminense vice-president Sandro Lima told A Bola.
“It will be a loan for a year, with an option to buy for Sporting. It is all well underway and I think that, in the next few days, everything will be settled.”
The player’s agent also confirmed he will travel to Europe next week to complete the deal.