Sir Bobby Robson believes Sam Allardyce's departure as Newcastle manager last night shows that the pressure on top-flight bosses is now 'too much'.
Despite arriving at St James' Park last May with a reputation as arguably Britain's best homegrown manager, less than eight months later `Big Sam' must now seek new employment.
Robson knows all too well the pitfalls of managing United after his transformation of a relegation-threatened club into Champions League qualifiers was rewarded with the sack by the previous regime in 2004.
And the former England coach claims the demands placed on managers these days are rapidly becoming intolerable.
'That's the eighth Premiership manager we've lost this season already. The pressure is too much now in the Premiership,' he told BBC Radio Five Live.
'The dismissals of manager are coming fast and frequent and it's rather sad for the game in many respects.'
He added: 'Like most people I was very surprised and stunned by the news.
'I was in his company on Tuesday night, I went to see Newcastle reserves play Sunderland reserves and Sam was there.
'So hearing the news was without doubt a surprise, and I am stunned.'
Hull boss Phil Brown was Allardyce's assistant during part of his time at the Reebok Stadium, and he disagrees with suggestions that United were too big a club for him to handle.
'He managed big players (at Bolton) - Fernando Hierro, Ivan Campo, Jay-Jay Okocha, Youri Djorkaeff, the list was endless,' he said.
'It wasn't just a case of managing a small club, it was managing big mentalities, and I think he went to Newcastle where the hardest part is winning the mentality of the fans over, and I don't think he did.'
Brown added: 'I have no doubt in my mind he would have won them round, his ideas were ground-breaking all the time I was working with him at Bolton, and ground-breaking ideas take time to settle in.
'It's unfortunate he didn't get the time.'
With Allardyce, once touted as a future England boss, and Steve McClaren, the ill-fated former national team chief, both now unemployed, Brown believes it is a sad time for the British game.
'We're looking at employing foreign coaches now at national level with Fabio Capello,' he said.
'Less than a couple of years ago you had Sam Allardyce and Steve McClaren going for the helm of the national team and now both are out of work - it's a sad day for British managers and coaches I think.'