The Slovenian teenager arrived at Elland Road on a year-long loan deal from AC Milan in August but has featured only twice for Leeds off the substitutes' bench.
The 19-year-old will return to England to begin his rehabilitation next week following surgery in Belgium to repair damaged meniscus.
Benedicic has been struggling with the problem for two months and his only appearances for Neil Redfearn's side have been as a second-half replacement in the home Capital One Cup win against Accrington and the league win against Bolton at Elland Road, both in August.