Chambers joined Castleford Tigers on Monday for a month's trial, with coach Terry Matterson hinting he could play a part in Sunday game.

But Castleford have since made it clear that the 29-year-old is not yet ready to feature in Super League, although he could play in the reserve match against Saints, which will be played as a curtain-raiser to Sunday's big game.

In a statement, the club said Chambers has undergone a full rugby league-related fitness test and will take part in training sessions tomorrow and Friday before a decision is taken on whether he will play
on Sunday.

Chief executive Richard Wright said: ''We wish to make our position regarding Dwain Chambers clear to our supporters and fans in general.

''He is with us as a trialist at this stage and is just beginning his rugby league education.

''We will continue to work with him on this basis so that both Dwain and the Castleford club can benefit from the experience.''

Chambers, who turns 30 on Saturday, was yesterday registered as a trialist with the Rugby Football League to enable him to play but he admits that a run-out with the reserves is a more realistic target for the weekend.

''It's come quicker than I expected,'' he told Sky Sports' Boots N All programme.

''Playing in the reserve team takes a little bit of pressure off me and lowers the expectations. It just allows me to get a feel for the game and see if I want to participate in a sport I've never experienced before.

''But I'm relishing the opportunity to play and I'm looking forward to it.''

Chambers, who is still considering appealing against a ban preventing him running in the Beijing Olympics, will not be paid for the month's trial and has been told he will have to prove himself if he is to land a £60,000 contract.

He said he has enjoyed the training so far but accepts he will become a target when he plays his first match.

''I've taken to it like a duck to water,'' he said. ''I seem to be a natural but that's all going to show its true colours when I play my first game.

''I'm hoping I avoid a lot of the hits but I am fully aware I'm going to get hit, it's part and parcel of the sport.

''I'm going to be a target but that will divert a lot of attention to me which leaves opportunities for other players to make moves and score tries.

''As much as I'm a threat, I'm also a diversion which is going to be a huge benefit for the team.''