THE Kangaroos will not be able to prevent Jonathan Hay from playing with another AFL club next season, should he choose to revive his career.

At least one rival club already has expressed interest in the defender, who retired last month following a contractual dispute with the Kangaroos, six months after detailing his struggle with bipolar disorder.

While he remains on the club's list, the 27-year-old did not sign anything as part of his contract release that would stop him from nominating for the pre-season draft and joining another team, either next year or in 2009.

Hay had two years left on his contract when it was terminated, and his situation is similar to that of Mal Michael, who retired and was released from the final year of his contract with the Brisbane Lions last October.

Michael decided less than two months later to come out of retirement and joined Essendon through the pre-season draft in December.

Because Hay is now uncontracted, the Kangaroos would have no choice but to delist him and watch him join another club if he chose to. However, that is a decision that would seem a long way off.

Kangaroos chief executive Rick Aylett would not discuss Hay's contract release due to confidentiality and said the club remained concerned only with his health, but confirmed it had "not put anything in place" that would stop the defender from going to another league club.

Aylett also said the Kangaroos would continue to seek AFL permission to upgrade a rookie to their senior list to replace Hay, rather than run a player short this season.

That plan already has been rejected by AFL football operations manager Adrian Anderson, who told The Age last week that the club knew before Hay retired that it could not promote a rookie.

"I don't really want to comment a lot on it because Jonny's welfare is the main thing and that's what we've all been focusing on. But we will address it and we will be talking with the AFL," Aylett said.

"The first step in our process was to notify the AFL that there was a change to the contract. We've done that, and basically we've got 21 days to provide them with more detail."