Gloucestershire cricket captain Michael Klinger will play for Western Australia this winter.
The 33-year-old, who has been playing for South Australia since 2008, had one year remaining on his contract.
The opening batsman wants to play for Australia in the 2015 World Cup but said he had been told that he was no longer certain of a place in the South Australia side.
Klinger is reported as saying: "I was disappointed and disagreed with the feedback I received. Two Shield games ago I scored a double-ton for South Australia.
"Without sounding arrogant, I feel I am too good a player to not play a full season of Shield cricket. I still have ambitions to play one-day cricket for Australia in the 2015 World Cup but if you are not playing Shield cricket you are out of people's minds."
Klinger rejected suggestions that his move was motivated by money.
"It was not a contract or money issue," he said. "The two years over one from WA helped, but I only had a guaranteed opportunity to play first-class cricket in one place. The hardest thing is leaving my team-mates. SA will have success soon and to not be part of that hurts a lot."