Injury-plagued Nick Kyrgios is backing his physical endurance as Lleyton Hewitt challenges his Davis Cup spearhead to step up mentally in his quest for an overdue grand-slam run.
Kyrgios could snare a precious top-16 Australian Open seeding after rising to 17th in the world rankings on Monday after breaking through for his maiden ATP Tour title in Australia at the Brisbane International.
Regardless of his seeding, the enigmatic star is now among the Open favourites, with world No.3 Grigor Dimitrov declaring Kyrgios almost unplayable during his Brisbane semi-final loss to the Canberran.
Kyrgios, though, has arrived at the slams similarly highly rated before, only to flop and mentally and physically break down.
More detaisl from Sports reporter Jeremy Eom.
