Slovakia Under-21 international Rusnak has linked up with Cambuur for pre-season training and he is thought to have impressed.
The 20-year-old shone in a midweek friendly win with two goals and two assists and Cambuur are believed to be ready to make an offer to take him on loan.
Rusnak will have another chance to catch the eye in this weekend's friendly with De Graafschap, with a host of clubs also expected to watch the midfielder in action.
It is understood that City are happy to loan out Rusnak so that he can gain some valuable first-time experience, with the player having previously spent time with Oldham Athletic and Birmingham City.
Cambuur are keen to win the race for Rusnak's signature as they look to build on a 12th-place finish in the Eredivisie last season.