Why is Pochettino already under pressure at Chelsea?

Chelsea are yet to score in the league in the month of September

The Blues hit a new low after a 1-0 defeat to Unai Emery’s Aston Villa

Mauricio Pochettino spoke after the game where he hinted what he believed was the problem with his squad

Zero goals in their last three matches. Five points in six matches.  Chelsea are in 14th place and sit four points out of the relegation zone.