Howard Webb believes Jose Mourinho should be sanctioned by the Football Association for mind games over the appointment of Anthony Taylor as the referee for Manchester United's draw at Liverpool.
United boss Mourinho has been asked to provide his observations to the FA by the close of business on Friday after responding to a question about Manchester-based Taylor's selection for the Anfield Premier League clash, which ended goalless. The FA will then consider its response, which is expected next week.
Managers, players and club officials have been prohibited from commenting on officials prior to a match since a new rule was introduced in 2009.
And Webb, the 2010 World Cup final referee, believes it is only right that that regulation is in place.
"The comments of Jose Mourinho before the game were not particularly inflammatory," Webb told Press Association Sport.
"It just adds oxygen to that debate, which is not helpful. He (Mourinho) knows that as well.
"Words sometimes can have an impact. That's why it's important that the FA are rigorous with their rules that managers who speak about referees before a game are sanctioned, even when it's said in a way that's less than inflammatory."
Webb says it is not possible to avoid such pre-match comments and, while officials remain neutral, the discussion might have a subconscious impact.
"People who talk about these things are trying to affect the subconscious mind," added Webb, who retired from refereeing after the 2014 World Cup.
"Undoubtedly Anthony Taylor would've had things in his mind. He would've been aware of what had been said.
"He would be aware that there was extra pressure on him, which wasn't helpful.
"It was fairly significant. I can't remember as much talk about a referee before a game for quite some time as there was involving Anthony Taylor's appointment for Man U-Liverpool."
Mourinho was responding to a question posed after Keith Hackett, former head of the Professional Game Match Officials Limited body, criticised the move, despite Taylor being registered with the Cheshire FA and being a fan of non-league Altrincham.
Similar scrutiny of an official last year prompted the PGMOL to remove Leicester-based official Kevin Friend from Tottenham's April game at Stoke, with Spurs then in pursuit of the Foxes in the title race.
But Taylor managed the occasion well, says Webb, who spoke up for his profession when Mourinho in early 2015 claimed there was a "clear campaign" against his then Chelsea side.
Webb says he was rebuked by Premier League chief executive Richard Scudamore for defending the impartiality of referees and later left his role as PGMOL performance director.
"We were coming under some significant pressure the year that I worked for the organisation that runs referees in this country," Webb added.
"We can take criticism, but when people start speaking about conspiracy theories and that referees are against a particular club, that's nonsense.
"I'm glad I spoke out about it. I was disappointed that I was rebuked for supporting the guys that I felt I was there to support in my role."
Despite that, Webb believes Mourinho is good for the English game. The Portuguese's United side play at Chelsea on Sunday.
"He is a challenge to the establishment, he is a challenge to referees as well; colleagues in Spain and Italy have said similar things," Webb added.
"(And) when the team doesn't perform he'll look for other opportunities to detract attention and sometimes that is towards the officials.
"(But) I like Mourinho being in the English game. He's a benefit to the league."
Webb dismissed only three managers throughout his distinguished career: Stoke's Gudjon Thordarson, Graeme Souness at Newcastle and Pep Guardiola at Barcelona.
Guardiola, now of Manchester City, was incensed when Webb booked Lionel Messi for diving during the 2009 Champions League quarter-final with Bayern Munich.
"It's more a penalty than a dive," said Webb of his only match refereeing at the Nou Camp, with the benefit of hindsight.
:: 'Man in the Middle' by Howard Webb, published by Simon & Schuster. £20, Hardback.