Beijing or bust? Nine days after he first picked up a rugby ball - for a photo shoot - it is likely that Dwain Chambers will find himself on the wing for struggling Castleford Tigers against St Helens on Sunday, the day after his 30th birthday.

But the gamble that Castleford are preparing to take is nothing like the one that Chambers is taking as a novice in an alien sport. An injury, and his continuing Olympic Games ambition could be brought to a painful and bitter end.

Chambers' jaw was not the only one that dropped as Terry Matterson, the Castleford coach, confirmed his intentions to give the club's newest recruit a chance at the earliest opportunity. Chambers had not envisaged being pencilled in to play so early during his month-long unpaid stint at The Jungle. In truth, neither had Matterson, but the bottom club's loss of two more outside backs to injury and the arrival of a nippy trialist (by all accounts) is forcing his hand. “If we can find a player, why not him? You can't beat raw pace,” Matterson said.

The danger with Chambers' twin-track journey of Olympic preparation and rugby league ambition is derailment on both fronts. He described himself as a “tough nut” but admitted to second thoughts on seeing the sheer physicality of a rugby league match on television while contemplating his move - and a baptism of fire in the engage Super League against St Helens, who will be merciless in kicking towards his wing, could end messily.

“I believe I'm going to be targeted, but I've been targeted all my life,” Chambers said yesterday. “But I went to American football, which is just as physical, and I got knocked around. The initial months were tough but I got on with it and enjoyed it. Coming to Castleford is a great opportunity to start my life all over again.”

Castleford will continue milking the publicity and an appearance by Chambers will guarantee a sell-out crowd on Sunday. The loser, though, could be the disgraced British sprinter. He may be the fastest man in rugby league, but his catching skills in American football were not up to scratch and hospital passes of the sort that he threw to Ryan McGoldrick, the Castleford full back, while playing up to the cameras would leave him exposed.

Training starts today with a gym session - “I'd expect him to lead the way in that one,” Matterson said - followed by skills work. Because Castleford have played and lost three gruelling matches in nine days, there is unlikely to be any contact work. If Matterson is satisfied and the player agrees, Chambers will be included on Friday in a squad of 19. Matterson could play him in a reserve-team curtain-raiser but sees little point. “The chances of him playing first grade are fairly high,” he said.

Despite having to be prompted by Nick Collins, his Leeds-based solicitor, about the number of players in a league team, Chambers was all smiles throughout his half-hour press conference. Asked about Sunday's match, he thought it might be too soon but added: “The coach calls the shots and, if I've got to go on the line, I'll be on the line.”

Collins, whose son is an academy player at Castleford and through whom contact is understood to have been made with the club nearly two months before Chambers won a silver medal in the 60 metres at the World Indoor Championships in Valencia, will spend the next few weeks pressing on with a legal challenge to a British Olympic Association lifetime ban imposed on Chambers after his two-year suspension for testing positive for the designer steroid tetrahydrogestrinone (THG), which ended in 2005.

“It's always been a very realistic aim we will be going to Beijing,” Collins said. “We wouldn't take an appeal on if we didn't think there would be a reasonable chance of success.”

Track record

Berwyn Jones
A British sprint record-holder who won a relay bronze at the 1962 European Championships, he played as a trialist for Wakefield Trinity under the alias of “Walker”. It led to a prolific five-year career with Wakefield, Bradford Northern and St Helens. Within nine months of converting, Jones went on Great Britain’s 1966 tour to Australia.

Alfred Meakin
A fellow member of the 1962 4 x 100 metres relay quartet; signed for Blackpool at the same time as Jones’s conversion.

Emmanuel McDonald Bailey
One of Britain’s finest sprinters, who in 1951 equalled the 100 metres world record of 10.2sec held by Jesse Owens and in Helsinki a year later won Olympic bronze. Became a rugby league professional with Leigh in 1953, at the suggestion of Eddie Waring, the commentator. He scored a try but suffered muscle tears in his only game, against Wigan – a gimmick to mark the switching on of Leigh’s floodlights.

Arthur Rowe
Oldham’s signing of the 1962 European shot champion did not work out.

Abi Ekoku
The conversion of 1990 British discus champion was more successful. He joined London Crusaders as a wing and later Bradford Bulls, for whom he played in the 1997 Challenge Cup final. He later became chief executive at Keighley and then Bradford and was Great Britain team manager for two years until last November.