West Ham manager Nuno Espirito Santo has called for clarity on what constitutes a foul at set-pieces, warning current levels of grappling and blocking are "almost crazy".

The Hammers boss became the latest Premier League chief to weigh-in on the issue as he called for refereeing officials to visit clubs and explain to players "what is a foul, what is a contact, how far can you go... because we are seeing things that are not normal".

Speaking before his side's FA Cup match against Brentford on Monday, Nuno revealed he had raised concerns with Howard Webb, head of referees' body Professional Game Match Officials Limited (PGMOL).

"What the referee has now allowed, what's happening in the set-piece situation is, I'll say, almost crazy," Nuno told reporters.

"I think they should review it. I can see that many of them are fouls - the contacts, the holding, the grabbing, the blocks.

"Many things are happening. Some of them are legal, some of them are OK, but most of them are contacts that go much further than what is allowed in football."

Earlier this month, Liverpool head coach Arne Slot...