Crvena zvezda sought to receive an amount close to 20 million euros for Vasilije Kostov, an 18-year-old Serbian attacking midfielder, and would not accept a lower amount, but Monaco wanted to pay half of that price. Numerous clubs were unwilling to meet the valuation, especially late in the summer transfer window. It was reportedly known that the Serbian club had not met its financial and sporting plans for European qualification. While Arsenal was an option earlier in the summer, Crvena zvezda was also waiting for a final communication from Inter or Milan, and the player had also been linked with Borussia Dortmund and PSG. If a transfer were to happen, Vasilije Kostov would remain at Crvena zvezda on loan. Kostov joined the club in July 2025 and has a contract until 2028. He has been capped three times for Serbia. His current market value, according to Transfermarkt, is €25.00m.