"Sam's been great. We're really fortunate that we've got a full squad training. We've got to the semi-final of a World Cup with the squad we brought over and we've still got everyone on their feet."
The Wayne Bennett-coached side are prepared for a torrid physical forward battle against a Tongan pack led by former Kiwis international Jason Taumalolo and ex-Kangaroos star Andrew Fifita, while they also remain wary of the Pacific island side's big and skilful backline.
"There's no secret to the way they play, they run hard and tackle hard and they've got some talented people within their group," he said.
"They've got two wingers (David Fusitu'a and Daniel Tupou) that could play basketball quite easily and forwards that can trample over the top of people and have played in massive games and huge test matches for New Zealand and Australia and also in State of Origin.
"It's going to be a massive challenge for us but that's what you want - you want this place to be banging tomorrow night with the Tongan supporters."
The 48-year-old former Great Britain and England international played 42 matches over three seasons with the Warriors, after arriving in Auckland for the club's inaugural 1995 season.
Betts was pleased to back in familiar surrounds and said his family had fond memories of his time down under.
"I loved my time here and loved being in New Zealand. Not just the playing side of things but the lifestyle and personal side of things, it was something that made me better and just the times I had here.
"My eldest daughter was born here, she's got a New Zealand passport. She was 21 two weeks ago.
"I know I look young but she makes me feel old."
