The Uruguayan international has been watched by the Magpies on several occasions this season and has been in red hot form in the Primeira Liga.
Nunez has fired his way to 20 goals in as many appearances and has also scored three times in seven Champions League appearances as Benfica progressed into the Round of 16.
The likes of Barcelona, Manchester City and Chelsea have all been linked with a move for the forward and Calcio Mercato journalist Rudy Galetti has suggested a fee of around £67million would see Nunez allowed to leave Estadio da Luz.
Sporting defender on Magpies radar
Portugal Under-21 international Goncalo Inacio is set to be a target for Newcastle.
The Sporting Lisbon centre-back has scored four goals in 19 league appearances this season as his side competes with Porto and Benfica for the Primeira Liga title.
Calcio Mercato have suggested the Magpies have watched Inacio on several occasions and could make a move for the defender this summer.
Inacio is believed to have a release clause of around £37million in his current contract.
Barca to beat Newcastle and Liverpool in race for Milan star
Newcastle were one of a whole host of clubs to be linked with AC Milan midfielder Franck Kessie.
The 25-year-old is set to leave the Serie A giants this summer when his contract expires and several Premier League clubs have kept an eye on the situation.
However, it is Barcelona that look set to win the race to agree a summer deal with Kessie according to Sky Italia reporter Gianluca Di Marzio.
Newcastle given hope in pursuit of Serie A hitman
Sassuolo forward Gianluca Scamacca has burst on to the scene this season with 10 goals in 25 appearances for I Neroverdi.
That form has brought him on the radar of the likes of Arsenal, Borussia Dortmund and RB Leipzig.
Newcastle have also been mentioned as a possible destination as they look to boost their options at the top end of the pitch this summer.
Sassuolo CEO Giovanni Carnevali believes a move away from Serie A could be the most likely scenario for Scamacca at the end of the season.
Speaking to GR Parlamento, he said: “The offer is more likely to come from abroad.
“Today in Italy there are some economic difficulties: maybe there may be the will, the desire to take on a player, but then I think the most important offers can come from abroad.”