Reading manager Jaap Stam
Stam caused a stir recently when he appeared to question the quality and intensity of West Ham's training after taking young star Reece Oxford on loan, as reported by the likes of Football.London saying Oxford had been surprised at the Royals’ intensity on the training pitch.
If West Ham's performances on the pitch this season are any reflection on training then it is hard to argue with the Dutchman.
Unfortunately for under pressure Bilic, though, Stam isn't the first to question the Croatian's training as evidence begins to pile up.
Against Sunderland last time out the Hammers twice threw away the lead setting a new league high 22 points dropped from winning positions this season.
They also picked up their fifth red card of the season when Sam Byram was sent off late on, more than any other team in the top flight.
It all points to a lack of discipline, a trait also highlighted by the likes of Enner Valencia, Simone Zaza.
Speaking to Everton TV - as reported by the Express - after signing on loan at Goodison Park for the season, Valencia said: "I have enjoyed training with my new team-mates, it’s different to my last team - it is a little bit harder."
West Ham United manager Slaven Bilic speaks with Simone Zaza
Then Zaza, who saw his loan move to the Hammers cut short in January as he joined Valencia, blamed the lack of training at his old club for his failure to make a success of his time in East London in an interview with Corriere dello Sport, as reported by Sports Witness.
Fans were puzzled too last week when legendary defender turned coach Julian Dicks made the shock admission that he did not do defensive coaching but shooting drills instead.
West Ham United owners David Sullivan and David Gold
And as popular as Bilic remains with a large section of the club's fans, it is clear something has to change.