Allardyce admitted: "In the Premiership you need your big players to be playing well, and that wasn't the case, certainly in the second half when we laid down far too easily.''
Allardyce added: "The lads who have been in have done okay up until now, but with our injury list we have begun to suffer, this match was just a bridge too far for our lads.
"We just aren't able to maintain things at the moment. We went into the game with great confidence and against a side who whose own confidence has been low.
"But we suffered for lack of height for their first goal, you can't make someone who is 5ft 11in into a 6ft 4in giant, and their flick on caused us problems.
"But in the second half we were bitterly disappointing, we just kept giving the ball away and that gave them the chance for their second and a place in the comfort zone. Even when we got an open goal at the end we couldn't score, that summed up our day.''