"That's the worst 45 minutes I have seen from my team since last Boxing Day at Preston,'' McCarthy said after the 4-1 home defeat.
"It was embarrassing, we were poor and it's not something anybody enjoyed. We were awful, all of us, including the staff as well.
"We got the goal we wanted after a few minutes but you could say we were a shambles in the second half.
"We will never know how much guts we have after they equalised because they scored so quickly again.
"Two of our more experienced players were involved for the second goal and that had a dramatic effect on some of the other players.
"In our previous games we have always had a chance of winning and I am not sure how better teams with better players would have reacted."