The Sunday Mirror dig up some old quotes:
We can reveal that the two have had a stormy relationship for over a decade, going back to when Barwick was in charge of the sports output at the BBC.
Despite winning the Premiership and FA Cup Doubles in 1994 and 1996 United were overlooked in favour of the Wigan rugby league team and the Olympic rowing and relay teams respectively for Team of the Year at the prestigious BBC awards.
They were finally honoured in 1999 after Ferguson led them to the Treble - and after Barwick had switched to become controller of sport at ITV.
A senior BBC source said: "Sir Alex was chuffed to bits when United won the award in 1999 and when he was named as coach of the year.
"But he always felt they should have had some recognition after winning the double in 1994 and 1996, and he felt the reason they didn't was because Barwick was in charge.
"After winning it in 1999 he joked that if Barwick had still been at the BBC United wouldn't have won it. A few weeks later someone told Barwick what Fergie had said and apparently Barwick said, 'Too bloody right'."
During Barwick's reign at the BBC, the United boss was convinced a bias had developed by the station against United and in favour of the head of sport's beloved Liverpool.
In Ferguson's biography The Boss, author Michael Crick wrote how Barwick had ordered John Motson to quiz the United boss about Roy Keane being sent off for the third time in 14 matches. The questions led to Sir Alex erupting in fury and Motson admitting he had been asked to ask them.
In the book, Crick also wrote: "Just as many Conservative and Labour politicians believe the BBC is biased against their parties, so Alex Ferguson appears convinced that the BBC is not just biased against Manchester United but is strongly pro-Liverpool.
"The regular presence of two former Liverpool defenders, Alan Hansen and Mark Lawrenson, as pundits on Match of the Day is seen as evidence of this, along with the fact that the former BBC head of sport Brian Barwick was openly a Liverpool fan."
The relationship between the two has remained cold ever since, so the news that Barwick will become the most powerful man in English football will not be greeted well in Manchester.
The club were already unhappy that Dein held such a strong voice within the FA despite his obvious links to their biggest rivals on the pitch.
But the feeling between United and Arsenal is nothing compared to the intense rivalry between United and Liverpool supporters.
United and the FA have had a series of run-ins over the past few years and supporters of the club are firm in their belief that the game's rulers have an anti-Old Trafford agenda. The club have always felt they have been treated harshly by the FA's disciplinary panel when players have been charged over poor behaviour.
But the uneasy relationship between United and Soho Square came to a head last year over the way Rio Ferdinand was suspended following his missed drugs test. Many believe the defender was given such a long ban only because of United's decision to take on the FA over their handling of the situation.
Neither Sir Alex nor United have commented publicly on Barwick's appointment. But a close friend of the United boss said: "It's clear the two have not always seen eye to eye over things in the past.
"But while Sir Alex remains suspsicious he is prepared to build bridges and ensure the relationship will not cause problems."