#5 Jurgen Klopp, Liverpool

With the club back in Europe's premier club competition, Jurgen Klopp's side garnered ambitions of putting up a real fight for the title at the beginning of the campaign but 3 draws against the so-called minnows (Watford, Burnley) and a morale-shattering 0-5 loss against table-toppers Manchester City coupled with drab draws against Sevilla and Spartak Moscow have their dented their season.
They even bowed out of the Carabao Cup, the only competition they've won in the last decade, in September. Major blame for the dismal performance lies with the German who apparently turned down the chance to sign Davinson Sanchez, now with Tottenham, and Napoli's Kalidou Koulibaly.
Loses in league games against the in-form Manchester United and Tottenham in the league, with the game against Maribor sandwiched in between, would certainly make Klopp's position untenable.