Phil Brown has demanded his Hull City side tighten up defensively after watching the Tigers produce a limp display in the 4-1 defeat at Sunderland.
To add insult to injury, Michael Turner, who only moved to the Stadium of Light from City a fortnight ago, was on the scoresheet for the Black Cats.
A non-plussed Brown admitted: "Conceding goals is between the ears where defenders are concerned and we weren't right second half.
"That takes work on the training ground and getting to know what playing for Hull City's all about.
"The new defence has to gel immediately. Ibrahima Sonko doesn't really know what I'm about but Kamil Zayatte certainly does and Paul McShane certainly does.
"We have about seven or eight new players now and maybe they need to know. The new players, whoever they are, they have to learn quickly.
"Before the game this was a game that we could have got something out of and I was positive of that at half-time but because of the collapse in the second half it's back to the drawing board."