"He's a supreme athlete, there's no doubt about that," said Kearney.
"In the last six weeks I've given him at stages sometimes seven minutes, sometimes 15 minutes and sometimes he hasn't played.
"For him to come on and play 40 minutes like that, I know he's very capable, so that's not going to be a worry for me."
Roache did more than plug a hole in the side, providing spark out of dummyhalf and tackling strongly to help contain Canterbury's formidable forward rotation.
A former five-eighth with the Junior Warriors (2014-15), he showed his ball-playing ability and pace when he burst through the defence before throwing a no-look pass to Shaun Johnson.
The No7 was dragged down short of the line but Bulldogs back-rower Josh Jackson was sin binned for a professional foul and the resulting penalty gave the Warriors an 8-2 halftime lead.
"I remember getting through the line and hearing Shaun's voice, because it's so distinctive to me - being a hooker, that's what I look for," he said.
"I looked to the right and he wasn't there, so I thought he must be on the inside and I just trusted that he'd catch the ball and he did which is lucky."
His recent good fortune comes after some tough times over the last 18 months, which have taught him the benefit of patience and how to overcome adversity.
A pectoral tear delayed his eventual NRL debut against Wests Tigers in round one of last season, and a troublesome ankle injury then required surgery over the offseason, before a thyroid operation further delayed his start to this year's campaign.
"They're pretty annoying things but some footy players have to go through that," he said.
"I think it's actually helped me, in terms of watching footy and taking a step back and learning new things about the game. And learning a lot about myself as well, about how to persevere and get through things like that."
Veteran lock Simon Mannering was not surprised by Roache's impact last week and expects he'll add more to the side once he really finds his groove.
"We all knew Nate was capable of that performance on the weekend and he'll be better for it and continue to grow as a player, said Mannering.
"He's very physical for a hooker and he's strong and very fast and very confident defensively, so I'm looking forward to him playing more minutes.
"He's more than capable. He's one of the fittest guys at training so he'll have no dramas."
Nathaniel Roache
Born: 14/4/96 (Age 21), Auckland
Height: 1.83m
Weight: 90kg
Position: Hooker
Rep Honours: Junior Kiwis (2016), NZ Residents 18s (2013-2014)
Junior Club: Richmond Rovers, Mount Albert Grammar
NRL Debut: Warriors v Wests Tigers, Campbelltown Sports Stadium, 5/3/16 (Round 1)
