Shane Warne says it will be difficult for Steve Smith and David Warner to recover from their "very harsh" punishment but he believes Australia need the pair back and at their best.

Smith, Warner and Cameron Bancroft were banned for their respective roles in the team's ball-tampering scandal in a Test against South Africa earlier this year, with the former two - the then captain and vice-captain - suspended for 12 months.

Warne believes Australia have suffered for the absence of their star men this year and he hopes they can quickly hit top form again on their return, having himself experienced a ban from the team when he breached Cricket Australia's drug code in 2003.

"It can be uncomfortable coming back but Australia cricket desperately need them back," Warne told Omnisport. "There is not enough talent coming up to replace players of this standard.

"They have played a lot of cricket, which I wasn't able to do, which is a surprise. I would have encouraged them to take their minds off cricket by jumping into something else.

"At the time, I thought the punishment of Smith, Warner and Bancroft was very harsh. For Smith and Warner to get a 12-month ban was a punishment that didn't fit the crime – they were playing against an opposition captain [Faf du Plessis] who had been done twice for ball tampering.

"It's hard for them to get over it as they'll always feel guilty. It was embarrassing. But they need to get back the respect of the Australian and worldwide sporting public."

Shane Warne's new autobiography: 'No Spin'. The definitive, intimate insight into the life and career of the world's greatest living cricketer is out now.