Jorge Linares has been forced to put his plans on hold after suffering another hand injury in last month's points win over Anthony Crolla.
The Venezuelan claimed the WBA lightweight title after an exciting battle with Crolla, which prompted calls for a rematch from both fighters.
But Linares sustained a fresh injury on his right hand in the sixth round and reportedly could be sidelined for up to seven weeks, which will force the 31-year-old to delay a proposed fight with WBC champion Dejan Zlaticanin.
WBC President Mauricio Sulaiman held talks with Linares last week and has decided to grant Zlaticanin a voluntary defence of his belt while he waits for the WBA champion to recover from injury.
Sulaiman said in a statement: "Linares injured his right hand in the sixth round of the ferocious battle vs Anthony Crolla, and after analysing the situation and confirming with Dr Jedediah Jones MD, it has been concluded that Linares will not be able to fight for some time.
"The WBC is hereby confirming that Dejan Zlaticanin is free to make a voluntary title defence of his WBC lightweight title."
Linares was made the WBC 'champion in recess' after a previous injury to his right hand forced him out of action for 11 months and Zlaticanin claimed the vacant belt with a third round stoppage win over Franklin Mamani.