The Hammers have begun their 2017/18 Premier League campaign in underwhelming fashion, and despite a crucial win over Swansea City last time out, they still find themselves in 15th position in the table, after a paltry return of just seven points from seven games.
Slaven Bilic already finds himself under intense pressure at the London Stadium, and the Croatian will surely have already identified some potential transfer targets for January, as he looks to improve upon his squad further still.
One particular area where he will want to strengthen is his forward department, with Diafra Sakho's future at the London Stadium far from certain and Andy Carroll's fitness issues still a real concern.
The Besiktas hitman is a reported transfer target for Tottenham Hotspur, Newcastle United and Crystal Palace, according to the Sun, but Bilic should make a major play to gatecrash the party in January.
The 26-year-old could be available for around £18 million, according to ESPN - an absolute steal in the current market.
Bilic still has an amicable relationship with the hierarchy at Besiktas, and he could use that to gain an advantage over the Hammers' London rivals in the pursuit of Tosun.
The Turk possesses superb technical ability, and would be an ideal partner for Javier Hernandez, should Bilic opt to play with two strikers through the middle.
And if the Croatian does manage to bring Tosun to the London Stadium, it could turn out to be a signing of real significance for West Ham.