ADELAIDE key defender Phil Davis will play with Greater Western Sydney next season, the first uncontracted player to join the Giants.

The Crows announced on Tuesday that Davis, 20, who will miss the rest of the season after a shoulder reconstruction, had told them he would be joining the AFL's 18th team in 2012.

Crows football operations manager Phil Harper said: "The club is extremely disappointed to lose a 20-year-old player who was a first- round draft pick with outstanding leadership potential.

"The club recognises Phil's honesty in coming forward this morning to inform his teammates of his decision, soon after he made it on the weekend.

"To lose another centre half-back after the loss to Gold Coast of Nathan Bock last year is certainly not ideal.

"I can ensure all our members and supporters that we did everything in our powers to get Phil to stay, including putting forward an offer well in excess of any offer to an 18-game player in the club's history."

Davis was selected with pick 10 in the 2008 NAB AFL Draft. He made his AFL debut in 2010.

GWS CEO Dale Holmes said AFL rules prevented the club from signing an uncontracted player until the end of the season, and he was only prepared to say that the Giants had "discussed an opportunity with Phil’s management during the year".

He said GWS would recommence negotiations with Davis' management once the season was over.

"We have a very clear list development plan and have a commitment to our members, supporters and the club as a whole  to secure the best talent that is available," Holmes said.

"Phil is an exciting young player with a big future ahead of him. We are delighted that he has indicated his interest in joining the Giants and believe he would be a very good fit for this club as we build a strong team for the future."