31 goals have been scored by Wolves this season but in contrast their defence has been breached 21 times – the third worst total in the division.
In total their last five games have seen them ship 14 goals as they start to stutter after a brilliant start to the season.
They got themselves somewhat back on track at the weekend with a 3-2 win at Watford in a match that McCarthy said “could have ended 6-6”
Speaking to the Express and Star, the former Republic of Ireland boss said “I lambasted the players afterwards – I gave them the sharp end of my tongue because we shouldn’t have made it so difficult for ourselves.
“We’re a sieve at the back and we have to change that. Either we defend better individually or collectively or we’ll have to do something else with somebody else.
“We made some real mistakes and defended poorly at times. It was a real scrappy affair with some rubbish defending and rubbish attacking which could have finished 6-6!
“We can’t afford to let 14 goals in in five games. Birmingham keep nicking games and they don’t give many goals away – eight this season.
“They haven’t been scoring many but they’ve been solid. That’s a promotion-winning outfit.”