Bree was playing centre back until Elphick came back - that was four games ago (and Hause is now here). Instead of sticking with Bree and keeping Hutton at RB, he changed the defence again in every position except Chester's. After the Wigan debacle would have been a good and appropriate time to "rest" Chester, but despite being appalling in that game he kept his place. I know it's a short period of time, but if DS was willing to throw Hause in against Wigan with 20 minutes left then why not try him from the start in the next game or keep Bree in there?
When you're conceding goals at the rate we are and playing as poorly as Chester has, surely anything is worth a try.... I like Chester, I really do, but he's been in poor form for a few months now and a rest is clearly what he needs.