Sunderland boss Roy Keane had admitted he has paid the price for having to use players when they are not fully fit this season.The Irishman has invested around £44million in new signings during his 18 months in charge at the Stadium of Light as he attempts to re-shape his squad for last success in the Premier League.

However, for much of the current campaign he has been forced to contend with an injury list which has robbed him of key men at regular intervals.

Kieran Richardson, a £5.5million signing, and influential winger Carlos Edwards, have been among those who have suffered most, with both having seen early comebacks put on ice after setbacks.

Keane, who freely admits he is learning his job as he goes along, is aware his club has been punished for gambling on the fitness of their recovering troops, but insists at times, he has had little option.

He said: "That is why in an ideal world, you want a bigger, stronger squad.

"I am always looking at the bigger teams and what they tend to do, and if there is any doubt about any of their players, then they just won't play them.

"But beggars cannot be choosers. We have not been in that position. We have had to ask the lads to push their bodies.

"At this stage of the season, players may be physically and mentally getting tired."

The fact that Sunderland have been engaged in a battle for survival for much of the campaign has not helped matters.

In more than one occasion, injured players have indicated their willingness to answer the club's call, only to get injured again.

Richardson succumbed just minutes into his return from a hamstring problem at Liverpool on February 2 and is unlikely to have recovered again in time for Saturday's trip to Portsmouth.

Similarly, defender Danny Higginbotham played on for several weeks with a broken toe and later had to undergo surgery to repair the damage.

Keane said: "The danger when you ask any player - I have done it many times - 'Are you fit?', is any decent footballer will, say, 'Yes, I am fit', especially with the situation we are in.

"Kieran had trained well all week - but training, let me tell you, to going into a Premier League game, is chalk and cheese. It is completely different.

"That's what we have been maybe a little bit guilty of - maybe with Kieran, not with other players - and we are paying the price a little bit now.

"We had to play Danny Higginbotham with his injury for three or four weeks because we had nobody else, and Danny now is out for a few weeks because his toe got a lot worse."

Meanwhile, £5million summer signing Michael Chopra has admitted he is desperate for a chance to prove himself as a striker once again after playing much of his recent football as a wide midfielder.

The 24-year-old has just three goals to his name for his new club this season, but is confident he can return to the sort of form which brought him 22 for Cardiff in last season's Championship if he gets the chance.

Chopra told the Sunderland Echo: "I will play anywhere in the team as long as I am playing.

"But I would like to play up front more times than not because that's my preferred position and that's where I think I do myself justice.

"But if the manager needs to do a job on the right or the left, I will be happy to do that.

"My form has not been particularly good this season. But I know that will change - and hopefully, it will change quickly."

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