Ognjen Ugrešić was a potential replacement for Arne Engels at Celtic but appears to be moving to PAOK. According to Partizan president Rasim Ljajic, Celtic offered £400k more than the Greek side in a package that would have reached almost £7m, but it was rejected. Ljajic stated that it is true Celtic offered more than PAOK and the €500,000 difference would have been very significant for Partizan in its current situation. The president explained that they had made a promise to PAOK and did not want to damage the fraternal relations between the clubs, which for them is much more important than the profit they would make from the potential transfer to Scotland.

Celtic made a last-minute attempt to sign Ognjen Ugrešić from Partizan after the club had accepted an offer from PAOK. The Glasgow-based club proposed a deal worth €6,500,000 plus €1,500,000 in bonuses and a 10 percent sell-on clause. Partizan rejected the offer, with president Rasim Ljajić stating they had already made a commitment to PAOK.