Traffic on Wheldon Road pulled up to a wire fence to watch a familiar figure in borrowed tracksuit bottoms high-stepping his way up the adjacent training pitch at Castleford Tigers. For the next hour, Dwain Chambers ran, caught passes - some of them, anyway - wrestled, burst through tackling pads and tried to stand his ground as bruising 18st forwards hurled themselves his way.

You could see him flinch but he brushed each runner off with his tackle guard, sending the odd one to the ground with what could be interpreted as a stiff arm. Through the grimaces, Chambers smiled a lot, even when he had his chin in the turf, and Awen Guttenbeil, the Castleford captain and former New Zealand forward, was acquainting him with rugby league's pleasantries.

Sprint training was never like this - a 50metre burst down the track and a six or seven-minute cool-off. After an hour of drills, Chambers, still grinning but sweating heavily and swigging from a bottle of water, sloped off to continue his one-to-one training programme with Dean Riddell, the Castleford strength and conditioning coach, while the first team worked on tactics for Sunday's visit by St Helens in the engage Super League.

Despite Castleford's bravado early in the week, a debut at the weekend was never a genuine possibility, with Terry Matterson, the Tigers coach, finally admitting yesterday that it would be “dangerous” to throw him straight in. The club, with their press officer on holiday and having got carried away by the media circus that attended Chambers's arrival on Monday, had earlier been reminded by the RFL of the operational rule stating that any player included from outside the first-team squad “must be of Super League standard - determined by the performance department”. Any attempt to play Chambers in a reserve-team curtain-raiser on Sunday would be interpreted by the League as a rule breach. Had an official from the governing body's performance department been at The Jungle yesterday to watch Chambers go through his paces, they could only have concluded that he is nowhere near ready; in his month's trial, will he ever be ready?

Full contact training comes next week, by which time Chambers will have his gumshield and headguard fitted. One of the biggest obstacles, though, is his fitness. “He is used to anaerobic exercise to build power,” Riddell said. “Bouncing the medicine ball on the car park, he's banging into the ground harder than anyone. But he's not used to aerobic activity. He has no endurance. We're having to deconstruct him as a sprinter.”

Questions about Castleford's insurance cover for Chambers continue to be brushed off. In training, Chambers is insured personally, although as Riddell pointed out, one injury could end any chance of him running in the Beijing Olympics this summer. “A simple cork [thigh injury] and you never run quite the same. Fair play to the guy for having a go,” he said.