Don't see too much of a problem tbh, we had a clean sheet against spurs and conceded against Liverpool just after okore had come on and was still getting into the game. In both games we managed to defend pretty well despite hanging on to a one goal lead.
As for yesterday, 99 times out of 100 guzan doesn't fluff his lines and Richardson and Bacuna need to be told to stand in the wall properly. Those 2 goals had absolutely nothing to do with ability ( or lack of ) so I don't think a big shake up is necessary.
I'd be quite happy going into next season with the same 5 cb's, Hutton and Bacuna at RB and Aly at LB. Don't think Richardson is good enough so would like a new LB though as competition for Aly.