West Ham United boss Sam Allardyce has hinted Premier League refereeing is in crisis.

Allardyce wrote in the London Evening Standard: "There are some who believe that refereeing in this country is nearing a crisis.

"What do I think? I can't say what I really think - and that in itself speaks volumes.

"I have an opinion - an honest one but I can't articulate that publicly because, as Jose says, punishment will follow.

"What I would say is that no one is questioning the integrity or honesty of our match officials. They try to do their job to the best of their ability. Like managers and players they are human beings - they can have good days and bad ones.

"For me, the problem is that the system is failing - and has been since professional referees were introduced 14 years ago."