The 19-year-old has become a regular summer training partner of the WorldTour veteran who helped line up his big break in the sport's continental hotbed.

Having begun riding with TIS Racing, Johnson continued his development this year with Drapac-Cannondale before signing another one-year contract with UK-registered team Trinity Road Racing.

"I'm really excited about it," he said.

"I'll mainly be racing under-23 events in Europe. It's only a small team but focused on turning as many riders pro as possible.

"It's the best option for me to move up and this team knows how to get you there.

"Europe is where it's at if you want to move up and to get this opportunity with some of the best under-23 riders in the world, I can only improve.

"I cannot wait to race over there."

The Cairns-born former Evandale, St Pat's and Launceston College student has made solid progress with Drapac.

He contested the under-23 road race at national championships at the beginning of the year before a seventh place in the individual time trial at the Oceania Road Championships in Evandale in March.

Johnson also completed the Herald-Sun Tour before heading to Europe, embarking on a few races in Belgium and training with fellow Tasmanian Will Clarke in Girona.

Returning home, he jumped head first into the National Road Series, playing a key role in the Tour of Tasmania at the beginning of December.

"This year I've learned education is very important," said Johnson, who is studying health science at the Launceston campus of UTas.

"You have to do uni to be in the team and the structure of team support has been superb, it has a very professional feel."

Porte is delighted to see Johnson progress having witnessed first-hand his potential as a fellow climbing specialist.

"You see a kid like Zach, he's just 19 and he's keeping me honest on the climbs and I think that's exciting that there's a future generation," said the 34-year-old Trek-Segafredo rider.

"He's not the most experienced guy but I honestly don't see anyone that's going to be able to climb with him if he keeps improving the way he is. The sky's the limit for him.

"He never misses a day, he's always on time and his bike is always immaculately maintained.

"The only thing he lacks is experience and he'll get that next year.

"When he learns to ride in a bunch with a good team around him he can make a good career out of the WorldTour if he keeps improving like he is. He's going to be a star."