The Magpies are working through an alternative list of targets after Reims youngster Hugo Ekitike stalled on a move to Tyneside before joining Ligue 1 champions Paris Saint Germain on a season-long loan.
United seem likely to meet a similar response over their reported interest in Leicester City winger Harvey Barnes, who is said to command an asking price of around £50million.
An alternative option has been provided by La Liga giants Barcelona after they told Dutch international forward Memphis Depay he was free to leave the Camp Nou.
Reports in Spain have suggested the former Manchester United star has been informed he has no future with Barcelona following the arrival of Raphinha and Robert Lewandowski and has been offered to a number of clubs in recent weeks.
Newcastle were named as one of the clubs contacted by the Catalans as they look to reduce their wage bill following a hectic summer in the transfer market.
Depay has enjoyed a productive first season in Spain after scoring 13 goals in 37 appearances in all competitions - but it now seems highly likely it will be his only year with Barcelona.
The 28-year-old spent a largely underwhelming two-year stint in the Premier League with Manchester United after moving to Old Trafford in a £30.6million deal in the summer of 2015.
He recently discussed the possibility of departing Barcelona amidst links with a number of Premier League clubs, saying: “I came here at Barcelona with the desire to play for the team - and of course I want to feel important here for several years.”
Spanish outlet Sport have reported Depay has already turned down a potential move to Tottenham Hotspur and will likely offer a similar response should Newcastle make a move to secure his signature over the coming weeks.