Gudelj has revealed he came close to joining the Viola last week.
"I could've gone to Fiorentina, but it all collapsed at the last minute because we didn't have time for the bank guarantees," said Gudelj.
"It was a hard blow for me to take, but fortunately my father managed to console me.
"Now I will get back to work for NAC, but if all goes well then I can complete the transfer in January.
"I am happy at my current club, although my ambitions always take me higher."