Newcastle have been offered the chance to sign Gremio striker Luan for around £17.5m ($25m), according to reports.
Sun on Sunday says the 24-year-old, who has been linked with a move to Liverpool, could join Newcastle before the January transfer window closes if they meet Gremio's asking price.
Magpies boss Rafael Benitez is in the market for a striker after losing confidence in Aleksandar Mitrovic and is trying to negotiate a deal for Feyenoord forward Nicolai Jorgensen.
Sky Sports reported that Newcastle had made two bids for Jorgensen, the second of which was worth £15m ($21m), but they were both turned down by Feyenoord.
Luan denied last week that Liverpool had approached him with an offer to move to England.
"If I knew, I wouldn't hide. I always said that I would leave it to Gremio and to my agent, and if they had something concrete, they should talk to me," the Brazil international was quoted as saying by the Liverpool Echo.
"No one has come to me so there is nothing. It has to be good for me, it has to be good for Gremio. I will not rush to want to leave soon, just like in the middle of last year.
"For the moment that we were through, I decided to stay. It was my decision alone. Now it's the start of the season and I want to regain my form and rhythm to play.
"What I know is that I want to play the next game as soon as possible here at Gremio."
Newcastle have also been linked with moves for Liverpool duo Danny Ings and Daniel Sturridge in January, but the latter looks set to complete a loan move to Italian side Inter Milan.
The Magpies pursued Deportivo La Coruna striker Lucas Perez and Monaco's Stevan Jovetic in the summer, but both transfers failed to materialise.