Time to invoke Disraeli. 3 clean sheets yes, but 2 of those against Norwich, who rested several players for the Cup game and have just lost 3-0 to defensive maestros Bournemouth, and a Palace side who sans Bolasie have completely forgotten where the net is. Shutting out Everton was creditable, but in truth, they showed very little ambition in that game and seemed to play for 0-0 from the outset.
For prime evidence, take a look at Lukaku's winner in the League Cup or Delaney completely unmarked but firing a point-blank range header straight at Hart. And if you are then still wavering, pull up the game at White Hart Lane.
Yes it is something of a risk putting Sagna in at CB, but he is a seasoned professional with experience in that position and has been playing at a way high level than MDM this season. Moreover, we have to make this move at some stage. We can't bet anything on Kompany's fitness and going into a very busy post-Feb period in 4 competitions with just 3 CBs, one of whom is MDM (who is nowhere close to a high class CB any more) is at best rolling the dice, more realistically utterly foolhardy.