"When I left school I was trying to keep on track but my diet was not the best and I started to beef up a fair bit," he recalled.
"At the trials I was pretty overweight and did all right but when Mike saw me he told me I needed to be in the front row.
"I went to Christchurch and did a few scrum sessions with Mike and he was extremely helpful in setting me on the path to where I am today."
Assistant All Black coach Steve Hansen got in on the act, too. He was involved with some team sessions and echoed Cron's thoughts about Kepu's future position.
"I thought I'd sneak back to No 8 for my Manurewa club and also for Counties but Hansen heard about that somehow and advised me I should be getting back to the front row," Kepu recalled.
The 125kg prop rocked on and made the NZ under-21s with Charlie Faumuina as his tighthead colleague and Owen Franks as the reserve to cover both sides of the scrum. In 2007 they played and lost to Canada when Franks came on to share the front row duties with Kefu.
"It was pretty special. I've had a bit to do with Owen since and we catch up after Super 15 games and get to talk a fair bit. He has done very well and is one of the top tightheads in the world at the moment.
"He was always a good prop but last year and this he was looking very good, he has improved markedly and I know he has worked very hard with his brother to get into top form."
After disappointment at missing out on a Chiefs contract for the 2007 season, Kepu was then badly injured playing for Counties against Auckland. He was not overjoyed with his rugby in New Zealand when Waratahs coach Ewen McKenzie came calling.
"I thought it was about time to push on, I was looking for opportunities," he recalled.
"I had been in the wider training group with the Chiefs but got no further. I wanted to play Super rugby. I felt I had done my apprenticeship, I had been taught a lot but I wanted to play."
He felt his promotion was blocked by props like Simms Davison, Ben Castle, Natahan White and Deacon Manu. They did not look like moving, so Kepu did.
He helped celebrate his brother's birthday in December then flew to Sydney the next day and made his debut for the Waratahs against the Highlanders the following March. He was on his way and later that year was taken on his first Wallaby tour.
His impact was not significant and he missed much of last year through injury. But that absence allowed him to get in a significant pre-season workload with the benefits showing this year. He also worked hard with forwards coach Michael Foley getting in extra tuition on playing loosehead.
Then came disaster in round 13 against the Sharks, when Kepu hurt knee ligaments and his Super season was over. He wondered whether that would also be his test chances gone.
But as he recovered, the Wallabies premier loosehead Benn Robinson hurt his knee and Kepu was back as the senior selection playing in the tests against Samoa and the Springboks.
"First up Ewen McKenzie helped me a great deal when he told me he wanted me to learn both sides of the scrum with the Waratahs. That versatility has helped me a great deal, it gave me a lot more confidence and it is second nature now."
Eden Park used to be home for Kepu, his family and his mates. He always used to go to open days for the Blues supporters. It is familiar but now foreign dirt. His parents and in-laws will be at the test tomorrow, apparently supporting the Wallabies.
"We are all excited about this match. It will be special playing at a ground I knew well, with everything up for grabs," he said.
Deans had brought renewed vigour and ideas to the Wallabies, he had broadened the group's knowledge and worked them all hard.
"But he manages to get the best out of all of the forwards and the backs," Kepu said.
