I'm not very familiar will the Serbian League however, I think you are going to need a good defensive midfielder to control the middle of the park.
One Serbian player that stands out to me in FM is Gojko Kacar for Hertha BSC who has worked really well for me in England when I played as Newcastle. He can play centre-back, defensive midfield, centre-mid. Really flexible and is good all-rounder. I know your looking for some-one with experience, he is 22 at the start of the game so if your a few seasons in he will will be mid to late twenties.
If not Dejan Stankovic is a similiar style player but much older.
One Serbian player that stands out to me in FM is Gojko Kacar for Hertha BSC who has worked really well for me in England when I played as Newcastle. He can play centre-back, defensive midfield, centre-mid. Really flexible and is good all-rounder. I know your looking for some-one with experience, he is 22 at the start of the game so if your a few seasons in he will will be mid to late twenties.
If not Dejan Stankovic is a similiar style player but much older.

