I'd drop Davies but he's looked to be improving from his ****house performances earlier in the year and would worry it would only extend his terrible form. Then again you cant drop Chester because (imo) he's the best centre-half we have, Dawson looks good whenever he plays and both Maguire and Bruce have been in top form.
Problem is, if we play a back 3 again, there wouldn't be a left sided centre half if we used Chester, Bruce and Maguire. Remember centre halves have their preferred side to play much like full backs or wingers, and both Chester and Maguire are absolutely right siders.
Whatever Quinn lacks in end product he adds in energy. When he plays we seem to pass better as a team and more importantly keep the ball on the deck.
Quinniesta was robbed of Player of the Season by Elmo the season we got promoted. He's a superb player. Thankfully he won Players' Player of the Season.