"He won't be fazed by the big crowds or big arena or even the crowd that will be against him, because there will be a lot of booing and yelling and screaming.
"He's progressed faster than what I thought. I didn't think he'd be in this situation for another couple of years, but here he is - here's his chance. I know he'll grab it with both hands and do it. I give him a good show of winning - not only because I used to have him.
"He's proved in the past that he can rise to the occasion. I had him on three or four occasions where he was the underdog big-time and he came through and won. I think he can do it again.
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"He was always quick, a very smart guy," Arkle said of the now 26-year-old Parker. "It wasn't until 2010 when we went to the youth Olympics in Singapore that he realised how good he was. I used to tell him he had the talent and could go a long way but he was quite casual about it.
"Once we went to Singapore and won a silver medal there, he said 'I know what you mean, I think I can go a long way and I'm getting more enthused about it'. Well, here we are."
Asked if he had ever seen Parker hurt, Arkle said: "No, he never got hurt and never got hit, which worried me because I always wanted to work on his defence and keep his chin down.
"When he went pro his chin was a mile high and his hands were low. They've improved that but because he was so fast he never needed to work on his defence and probably thought I was talking a load of rubbish at the time. But when you get to his level of boxing you've got to put it all together.
"He's got a great chin, Joseph, but you don't want to be giving opportunities away to a guy like Joshua – he hits like a train and he's fast. He's a lot faster than I thought he was."
Auimatagi Jr, 22, has a 9-1-2 professional record and is a surprising favourite against the undefeated Jones.
He said he knew Parker well – they used to train together as amateurs – and he was predicting good things at the Principality Stadium for the WBO world champion.
"I reckon he stops him in round 11," Auimatagi Jr said. "I had a dream. Joshua is lying on the canvas in round 11."
The storeman, with a fiancé and child on the way, has to fit boxing around his fulltime job. He said: "I'm nervous, excited – a whole mix of emotions. I'm really blessed to be here. I know all the fighters back at home in New Zealand would kill for the chance I have right now. I'm going to use the opportunity that me and my coach have to make my country proud."
