AVA- Zakhilwal had stepped back as ambassador two months ago, though his resignation was not accepted by the president.
The Afghan government has not confirmed appointment of Mashal, who had earlier resigned as cricket board chairman and was replaced by Azizullah Fazly, Zamannews reported.
Mashal has not commented about his appointment as ambassador, neither has Zakhilwal reacted.
There has been a wave of resignations in recent months as time window for parliamentary elections is winding down and presidential vote looming. Last month, Afghan ambassador to India Shaida Mohammad Abdali quit, although no one has been appointed to replace him so far.