Reds fans have seen 'no where near the best' of Brek Shea, says Reds boss Danny Wilson.
The American winger – who is on loan from Stoke until April 3 – has struggled to make an impact in five starts and a substitute's appearance on Tuesday night at Wigan.
Wilson said: "Brek has had food poisoning recently and missed a game but he would say that even before that he's not been at his best. We've seen flashes of brilliance but he's not been consistent.
"He has got high aspirations to play in the World Cup for America and to do that he needs to be firing on all cylinders. He's very frustrated with his own form."
Another player who has failed to live up to the hype generated by his signing has been Norwegian international Marcus Pedersen. Wilson said: "He's been injured for long time and he's still not fully fit. Since I have been here I think he' s only been available for two games and he has not trained very much. We're hoping he will be fit soon and pushing for a place."
Wilson also agreed with predecessor David Flitcroft that Polish winger Tomasz Cywka should be used as an 'impact sub' rather than a regular starter.