I put a comment in the Sterling thread but it's just as relevant here:
"Three players who are playing below their potential, Stones, Sterling and Mahrez all seem to have relationship issues ATM or in the recent past, that are likely proving a mental distraction. Hopefully with the right support this situation will improve soon?"
In Mahrez's case he has certainly seemed the innocent party. As fans it's frustrating when players are performing below par, but sometimes player's need support to help them through difficult times.