With just 19 goals in 20 games, finding the back of the net has been an issue for the North-East side. Aleksandar Mitrovic has only managed six appearances so far, scoring once and now, the Serbian forward has admitted he will have to leave St James' Park.
“I persistently waited for the chance of the past months. I'm sorry after all, I loved Newcastle, but it's time for me to look more at myself, to find the best solution for my career,” he told Serbian website Zurnal.
“I never felt better, I'm physically in flawless form, I cannot wait to play. The most important thing is to find a club and finally get a chance in the field.”
His departure would leave the Spanish boss with Dwight Gayle, Joselu and Ayoze Perez as his main attacking options. Signing a striker in January should be the club's priority.
Here are five strikers Football Whispers believe Newcastle should target in January.
Michy Batshuayi – Chelsea
A £33million signing from Marseille in the summer of 2016, Batshuayi has struggled to settle at Chelsea. He's been unable to crack Antonio Conte's first team on a regular basis, despite the fact he invariably finds the net whenever he is used.
The 23-year-old Belgian's position at Stamford Bridge was further undermined by Chelsea's (ultimately doomed) pursuit of Fernando Llorente in the summer, a move which would've seen Batshuayi become the third-choice striker for a team who tend to only play one up front.
If Chelsea don't want him, though, there will be no shortage of takers for Batshuayi. The deadly poacher has averaged a Premier League goal every 68.4 minutes since joining the Blues and would improve most sides in the division.
Cédric Bakambu – Villarreal
Having finally overcome the injury troubles that plagued him for a large chunk of the last 12 months, Bakambu is now back to his best and firing on all cylinders for Villarreal.
The pacy Congolese striker has already notched nine goals in 15 La Liga appearances this term, and looks set to deliver on the potential he showed upon moving to the Yellow Submarine from Bursapsor in 2015.
Still only 26, Bakambu has plenty of years left in the tank. His dynamic pace and ever-improving finishing would be an asset to any side.
Stylistically, the France-born star's ability to terrorise defences in behind and play quickly on the counter could offer up a whole new avenue of attack for Newcastle.
Antonio Sanabria – Real Betis
Paraguayan striker Sanabria is a former member of the Barcelona academy, and impressed in La Liga on loan from Roma with relegated Sporting Gijón last term, scoring 11 times in 30 games for the Asturian side.
His form with Sporting led to a scramble for his signature over the summer, which Betis won, paying €7.5million for the youngster, with Roma retaining a buy-back option and a 50 per cent sell-on clause.
Sanabria has already scored seven times in 12 appearances for his new club, demonstrating his pace, cool finishing skills and temperament for top-level football.
The clauses in the deal that took him to Betis this summer could complicate any potential move to the Premier League, especially so soon after joining the Andalusians, but the 21-year-old South American would be worth the effort.
Mark Uth – Hoffenheim
With ten of his 22 Bundesliga appearances last season coming from the bench, German striker Uth was somewhat under-utilsed at Hoffenheim. But manager Julian Nagelsmann has put that right this term, starting the 26-year-old 15 times to date.
And Uth has repaid his manager's faith with nine goals and two assists. An intelligent mover capable of striking the ball powerfully and accurately with either foot, the Cologne-born hitman is a threat anywhere in and around the penalty area.
Germany's wealth of talent means that Uth is still uncapped at senior international level, but there is no doubting his quality and propensity to sore goals on the highest stage.
Bas Dost – Sporting Lisbon
When studying Dutch poacher Dost, it is difficult to discern what exactly it is that he does well: the 28-year-old Sporting Lisbon striker isn't especially athletic; he doesn't have great pace; and he is not a skilful player.
But what he does to – and expertly so – is put the ball in the net. Very much the kind of striker who depends on service, Dost can be relied upon to dispatch chances at a thoroughly productive rate.
He left Wolfsburg – for whom he scored 48 goals in 117 appearances – to join Sporting in the summer of 2016, signed in a deal worth an initial €10million. Dost has thrived in Portugal, netting an incredible 36 times in 41 games last season and adding 13 in 15 so far this term.
He may not be the most glamorous option, but should Newcastle move for Dost, their goal-scoring ills would be cured.