"He has obviously given me a huge head start and he, Katrina and his owners have put me on some great horses.
"But I also need to keep learning and growing and shifting will help me do that.
"I wouldn't be where I am now without Barry and everything he has taught me and we still get on great.
"But the time to move is right and the Streets and Ray have given me a really good opportunity."
Purdon was also quick to laugh off the usual harness tittle tattle about a falling out.
"Zac will still be driving a lot of my horses including our best one Jack's Legend but he is only young and should get out and experience working for different people.
"And he is going to a good environment with Ray and John."
Butcher will make the move in April and already has an established relationship with Lincoln Farms.
"Zac does a lot of driving for us and we enjoy working with him," says Green. "And I am sure he will be great to have on the property as he is a pretty cheerful sort of a guy. We are thrilled to get a horseman of his standard coming on board."
Meanwhile, Kiwi pacing hero Lazarus will start a red hot favourite in the A$500,000 Hunter Cup at Melton on Saturday night.
The two-time New Zealand Cup champ has drawn perfectly at barrier three and is rated a $1.35 favourite by TAB bookies over stablemate Heaven Rocks at $6.
The draw for Victoria's richest pacing race mirrors that of the Inter Dominion Final Lazarus won in Perth on December 8, with Tiger Tara drawn the ace and likely to lead while Lennytheshark is drawn on his back and likely to be the closest stalker, similar to where he was in the Inter final.
Lazarus hasn't raced since his jaw-dropping second after being three wide throughout in the Fremantle Cup on January 12, after which he suffered hoof soreness.
"He is well over that and has been working great this week," says trainer Mark Purdon.