Australia's Davis Cup tennis coach Lleyton Hewitt revealed an unseen side to Nick Kyrgios after a topsy-turvy day of tennis which saw Australia end day one of the Davis Cup at 1-1 with Germany.
The former World No. 1 praised the polarising 22-year-old for his input in young gun Alex de Minaur's development as the 18-year-old star prepared for a national debut.
Hewitt said Kyrgios played an "older brother" role to the World No. 139 as he progressed through an outstanding month of tennis to kick off 2018.
"He's been fantastic with de Minaur," Hewitt told Channel 7 after the wiry star's epic five-set loss to Alexandr Zverev on Friday.
"He's sort of been his older brother. Even when Alex was the orange boy, he'd always get him out to hit with him and help him.
"They're the things that the public doesn't see Nick Kyrgios do."
Hewitt said the controversial Kyrgios — who recently won over a mountain of doubters in his stellar fourth-round effort at the Australian Open — matured in droves ahead of Australia's Davis Cup campaign.
"He's had to grow up very quickly in the spotlight," he said.
"I think he's really matured over the last six months and I think the Davis Cup has helped that."
Kyrgios leveled Australia's World Group first- round match against Germany on Friday with a 6-4, 6-4, 6-4 win over Jan-Lennard Struff.