The former skipper said that he will provide whatever advice or assistance Hafeez needed.
Stuart Broad tore his shoulder muscle while bowling in the Lord's ODI against India.
Australia's Twenty20 captain is looking to get the team off to a winning start.
It follows Ponting's decision last month to step down from international Twenty20 cricket.
Younis had announced retirement from T20 after the World Cup.
StarGaze: Katrina- Sidharth Visit Jhalak Sets, Tiger Shroff Promotes A Flying Jatt
LFW 2016: Jacqueline Fernandez, Swara Bhaskar, Saiyami Kher Add Glamour On Day 3
Bollywood's Most Popular 'Dahi Handi' Scenes
In Photos: The Asus Zenfone 3 With Glass-and-Metal Design
Enduring Images of Rio Olympics 2016