If this was the last Australian Open singles match of Nick Kyrgios' career — and, to be sure, it's hard to know with him, no matter what came out at his news conference — the big-hitting, big-talking tennis player went out rather quietly Monday night.

Alex de Minaur, the world No. 8, and Nick Kyrgios, who is back after a two-year battle with knee and wrist injuries, are the headliners for their country at Melbourne Park. Kyrgios emceed the night session on John Cain Arena Monday, before De Minaur headlines Rod Laver Arena, the pantheon of Australian tennis Tuesday night.

Nick Kyrgios has made several comments in recent months that suggest he may be closing in on retiring from tennis - the latest coming after his Australian Open defeat