Sunderland boss Roy Keane had admitted he has paid the price for having to use players when they are not fully fit.
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.
He said: "That is why in an ideal world, you want a bigger, stronger squad.
"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. Keane added: "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."