Arsenal manager Arsene Wenger and David Dein in the stands
Arsene Wenger memorably declared Dein's departure from the Gunners in 2007 as a "sad, sad day for the club."
The North Londoners have not won a league title since with Arsenal fans often citing Dein's knowledge, guidance and passion as crucial missing factors.
Eggert Magnusson at West Ham United
At the time, under the ownership of the doomed Icelandic consortium and chairman Eggert Magnusson, West Ham were exploring the possibility of a future move to the Olympic Stadium, which had yet to be built.
While it was actually owners David Sullivan and David Gold who eventually brokered the move to the 60,000 seater stadium, Dein's remarks were telling.
"We tried to do a deal with London 2012 but the real problem was we did not have enough money," Brown said back in 2006, as reported by the Independent.
"I think the new owners (the Icelandic consortium) are keen on the idea and there is a real possibility they will go down this path.
"It could be a fantastic development for east London.
"David Dein of Arsenal tells me the prospect of West Ham in the Olympic Stadium frightens him to death."
It is understandable why passionate Arsenal fan Dein was so fearful.
The West Ham support has always been recognised as one of the finest and most loyal in the country and true to form 52,000 of them signed up for season tickets at their new home - second only to Manchester United.
But the move has been a disaster so far with problems on and off the pitch and fans angry with the board after a string of broken promises over the new ground.
Polls on social media and fans forums reveal thousands of supporters are seriously considering not renewing next season such is their apathy for their new surroundings.
West Ham United look dejected
Dein probably feared the club would use their increased capacity and revenue streams to compete with the big boys in the transfer market.
But instead of building on Slaven Bilic's superb first season at the helm co-owners David Sullivan and David Gold have infuriated supporters by trying to do things on the cheap.
Together with Bilic they have wasted a golden opportunity to close the gap on the elite diluting what was a promising squad of players with loan signings and free transfers woefully short of Premier League standard let alone good enough to push the club on.
Dein spends much of his time nowadays as a public speaker but as his old side visits the London Stadium this weekend any fears he once had will have long dissipated as Arsene Wenger's side look to keep their title tilt on track while the Hammers scrap against the threat of relegation.