The former Spain U21 is said to have rejected interest from Barcelona and El Clasico rivals Real Madrid to sign for the Magpies in summer 2014 following a prolific spell in the Spanish second tier with Tenerife.
The 22-year-old has gone on to bag 13 goals in 70 Premier League appearances for the Tynesiders, including six strikes last season as they plummeted out of the top flight.
And according to The Daily Mail, who echo similar reports from Spanish publication Sport, Barcelona are eyeing the prodigious goal scorer once again.
The Nou Camp giants are in the market for another forward but have struggled to find one willing to play second fiddle to Lionel Messi, Neymar and Luis Suarez.
However, the are other options on the radar, not least including West Ham transfer target Carlos Bacca.