Dwain Chambers has been released by Super League strugglers Castleford after a month's trial.

The Tigers agreed to give the disgraced sprinter a month's trial but have concluded that, at 30, he does not have enough time to carve out a career in rugby league.

"Our coaching team feels that he would need a significant amount of additional time to prove whether or not he would be capable of making the grade in Super League and time is something that we don't have," said Castleford chief executive Richard Wright.

Chambers' manager Nick Collins said: "Whilst disappointed, Dwain is comfortable with and understands the decision."

Chambers, who experienced his first taste of rugby league in a specially-arranged reserve grade game nine days ago, must now wait to see if that high-profile friendly attracted enough interest from clubs outside Super League to make him an offer or call a halt to his daring move.

And his agent, Ron Hill, has revealed that there has already been interest in the athlete.

"I am in discussions with other clubs," said Hill.

"But it's got to be right from day one. It was all a bit rushed last time. I have had one or two clubs coming to me but it's got to be full-time.

"Dwain needs six months in the reserve grade and a full pre-season to learn about the game.

"We know he's mentally tough and he's got speed. He has come a long way in a short time and I think what we've seen in a month is enough to show there is potential."

Chambers spent 39 minutes on the field in four spells and clearly struggled to cope with the stamina needed to play the 13-man game before eventually retiring with a shoulder injury.

Chambers insisted, however, that he enjoyed the experience and Castleford say they saw encouraging signs in his performance.

Wright added: "Many people watched Dwain in the trial game and he has certainly won over some of the doubters and proved that the trial was more than simply a publicity stunt.

"During his trial period Dwain has been a joy to have around. His work ethic and professionalism have been exemplary.

"He has got on well with all members of the club's staff that he has come into contact with and he has been in great demand, proving a popular visitor to local schools. He has also given us a huge media profile.

"I believe that he feels that he has gained from his time with us, so there are no losers.

"All the club wish Dwain the very best for the future in whatever path he chooses to follow."

Chambers, who needs to pay back around £100,000 in prize money he earned during the time he spent taking illegal drugs, twice tried and failed to break through into American Football.

He has not yet ruled out a bid to overturn the British Olympic Association ban on him competing in Beijing this year and also has hopes of running in the London Olympics in 2012.

Sporting Life / Eurosport