Partizan currently sit on top of the Serbian Super Liga with just one loss in their past 11 games, although they have made a stuttering start in Europe with a draw against Neftchi followed by defeat at Rubin Kazan.
Vermezovic said: "Our young team has come to Milan to play a great game and gain experience for the future. We know what awaits us but sometimes the power and authority of youth can surprise."
Inter go into Thursday's game having won their past five in a row to move up to fourth in Serie A.
But Inter boss Andrea Stramaccioni, whose team sit top of the group with four points from two games, is not under-estimating Partizan.
Stramaccioni said: "We expect a team in good form who are top of their league with eight wins and just one defeat. They have talented players and we have a lot of respect for Partizan. We know it will be a tough game."
Stramaccioni is expected to make many changes to the side that continued their recent winning run in Serie A against Catania on Saturday, with Holland international Wesley Sneijder unlikely to be risked.
Sneijder has not played since suffering a calf injury in September and the Inter boss said: "He is highly motivated and wants to return as soon as possible, but they will only return if they are 100 per cent.
"I do not want to rush him back."