Roosters centres Joseph Manu and Latrell Mitchell.

Mate against mate: Mitchell's Test warning to Manu

They've played together since joining Sydney Roosters as 16-year-olds and credit opposed training sessions against each other for their rapid rise this season but rookie Australian centre Latrell Mitchell has warned Joseph Manu ahead of his New Zealand Test debut: "There's no mates on the field".

Mitchell will debut for Australia at left centre, while Manu has been rewarded for his role in the Roosters' stunning grand final victory by earning selection opposite him as New Zealand's right centre in the trans-Tasman Test at Mount Smart Stadium on Saturday night.

It is the first time the pair have been rivals after being teammates in the Roosters SG Ball and under 20s teams before both making their Telstra Premiership debuts in 2016.

"To play in the green and gold, and him for the Kiwis, it's an awesome achievement for both of us," Mitchell said on Wednesday as the Kangaroos begun preparations in Auckland for Saturday's Test. "I'm honoured and keen to go up against one of my mates.

"It's going to be a good clash. We train against each other … just to sharpen each other up. It's shown throughout the year with what we've done. We'll see what we do up against each other."

Yet according to Roosters teammates, the pair don't hold back when pitted against each other at training and they have promised to approach their Test debuts with the same aggression and focus on Saturday.

"There is so much competition there," Mitchell said. "We each don't want to be beaten by the other. That's why we tightened up in defence this year [at the Roosters] because we've been going hard at each other.

"I'm competitive, and he is going to be competitive. The aggression just comes out. People take it off for being grubby. It's just how I play to beat my opponent.

"He has some aggression there too. He is so strong, the last six months he has put on so much muscle. I'll give him the respect he deserves but then again, there's no mates on the field."

Roosters and Australian fullback James Tedesco said he was looking forward to seeing his teammates go head-to-head in the Test after observing their duels at training this season.

"I'm excited to see Joey versus Latrell," Tedesco said. "They will get a bit heated, they get a bit heated at training. Those two go pretty hard at it. When we are doing things at 50 per cent those two are going at 100 per cent at each other.

"They grew up together so they are both excited to come up against each other. Latrell is a great attacker and Joey is a great defender so that will be a good battle.

"Joey had a lot of tests this year against guys like Greg Inglis. He has nailed every one of them. Latrell has put some of the best centres on show in attack. It'll be a good test to see who comes out on top.

"Joey is very quiet, Latrell is a bit more outspoken. I don't think Latrell will be carrying on too much against Joey because Joey is too nice."