World No. 1 Jannik Sinner, who is about to return to action after a three-month doping ban, thought about walking away from tennis even while successfully defending his Australian Open title, but is coming back with a new mentality.

Sinner accepted a three-month ban in February after a settlement with the World Anti-Doping Agency, which had appealed to the Court of Arbitration for Sport against an independent tribunal's decision in August to clear him.

The Italian had tested positive for anabolic agent clostebol, which Sinner said entered his system from a member of his support team through massages and sports therapy.