I just think his standards have been lacking recently and Mahrez has started the season off in great form so deserves a run in the team.
Mahrez fully firing will score more and get more assists on the right than Bernado. Bernado will hopefully play on the right a bit less and more in the middle as the season goes on. In some home games it would also be good to see Sterling back on the right taking it past fullbacks at will with Jesus to the left of Sergio.