The 20-year-old striker, who is an ever present for the Slovenian Under-21 side, has been offered a one year deal at the Walkers Stadium.
Paulo Sousa's second signing since becoming Leicester manager has fuelled specualtion that French striker Yann Kermorgant is set for a loan move back to his home land, with a loan deal offered by AC Arles-Avignon likely to be completed over the weekend.
The Leicester squad travel to Oxford United tomorrow night for a pre season friendly and Crncic is expected to feature for the Foxes.