PCB Chairman Nasim Ashraf said on Thursday that efforts had been made to trace Yousuf but he was yet to be located.
"We don't know where he is. His phones are all switched off," he said. Ashraf said he was keen to have a talk with Yousuf and try to persuade him to give preference to country over money.
"He remains our best batsman and we need him in the coming years. I will try my best to convince him to abandon this ICL contract. This despite the fact that Yousuf didn't take us into confidence before joining the ICL."
The media speculated that Yousuf might have already left for Chennai where the ICL has started its training camp for the first series of matches in October and November.
"We want to talk to Yousuf and persuade him that though he might get money by playing in the ICL but not recognition and name which is only available if he plays for his country," Ashraf said.
The PCB chief said the board was thankful and grateful to all those players who had rejected ICL offers and decided to play for Pakistan.
"We appreciate their gesture and we know they have lost a chance to make some good money. We will also try to reward them soon," he said.
Ashraf said the PCB would soon meet to finalize a policy on players wanting to play in the ICL.