Godwin will leave Australian rugby at the end of the Super Rugby season after signing a deal to join Galway-based Connacht to play in the Pro 14 season.

It's another blow to Australian rugby's depth given Godwin is just 25 years old and has played just one Test for the Wallabies.

His decision to move to Ireland means he will sacrifice his chances of playing for Australia at the World Cup next year and any immediate international ambitions.

Godwin, who played 52 games for the Western Force before joining the ACT Brumbies, has already declared his intention to return to Australian rugby in the future.

But the fact Godwin is so young is another reminder Rugby Australia faces massive challenges to match big-money offers in Europe for rising stars who aren't established Wallabies.

"I had to have a deep, deep think about it. It was hard for me, but it's a new challenge and a chance for me to grow on and off the field," Godwin said.

"It's always been a dream of mine to play for the Wallabies and I knew by heading overseas I'd be giving up that for the time being. But I'm still young, so I do see myself coming back and pushing my case again.

"I thought this was the best chance for me to grow as a player. A new rugby experience will be a good thing for me. But I'm definitely going over with a sight to coming back to Australian rugby as a better player and a better person.

"I want to become more worldly and hopefully improve my rugby skills when I come back."

Brumbies coach Dan McKellar has reassured Godwin his decision to leave won't affect his selection chances for the rest of the season.

But Godwin is facing a challenge to win back his starting spot after Wharenui Hawera and Christian Lealiifano teamed up as a playmaker combination last week.

"I gave Kyle assurances that he's made the decision in good faith, I won't be not considering a player for selection based on what he's doing in six months," McKellar said.

"It's not fair on the player or anyone. We'll pick the team each week we think can win that game.

"I think [Godwin] improved and got better here. He's probably looking for an opportunity at a higher level and maybe he didn't see that right now. But he's at an age where he can come back.

"A few years ago you might have been surprised given his age, but it's becoming more common now."

The Brumbies are keen to keep the core of their squad together, with McKellar locked in player negotiations and keeping one eye on his roster for next season.

Lealiifano remains a major retention target, but the veteran is expected to be targeted by overseas offers after an impressive stint in Ireland at the end of last year.

Godwin says he won't start planning for his move abroad until he's achieved his goals with the Brumbies. He made his Super Rugby debut as a 19-year-old and has played 66 games, but is yet to get a taste of finals action.

"I've got a big heart for the Brumbies and I'm 100 per cent committed to making sure I can do everything to win the tournament this year," Godwin said.