The man who once fostered in a revolutionary era in London is now threatened in being swept up in one as Arsene Wenger and Arsenal list seemingly rudderless and try to right themselves.
Meanwhile in the sky blue part of Manchester, the transition to Pep Guardiola has not gone completely according to plan - revolution in the Premier League will have to come another day.
Sunday's mouth-watering clash at The Emirates between Arsenal and Manchester City has more than top-four positioning at stake. It's about whether the game has passed by Wenger and his ideology, while Guardiola continues to plot his course to bring another Premier League title back to the Citizens while claiming European glory.
These twin flameouts in the round of 16 in the Champions League - one now an annual ritual for Arsenal (15-5-7) and another two steps backwards for Manchester City (17-6-5) when compared to last year - have shown the frailty at the top of the Premier League on the European stage.
All the money lavished on star players has brought little return on investment for these high-powered clubs, yet defending Premier League champions and relegation-threatened Leicester City are in the final eight of Europe's most glamorous tournament. Though that only came about after a managerial change that on the surface reeked of desperation but turned out to be the correct decision given their response in form.
It is that type of response which has galvanised the "Wenger out" or more cheeky version "Wexit" for those among the Gunners supporters who want a change. The consistency of a top-four finish - something which is in no way guaranteed considering Arsenal need to at least not lose this match - has also dulled title ambitions domestically, which makes those European failures all the more grating to the faithful.
And there have been points where Wenger has done little to reverse these trends. An example was in the reverse fixture at The Etihad, in which Guardiola recognised the deficiencies of his side and tactically adjusted his midfield at intermission trailing 1-0. That impetus led to a reversal of momentum and goals by Leroy Sane and Raheem Sterling as City rallied for a 2-1 victory.
Another example came before the international break, when Wenger claimed his side were fully prepared to neutralise West Brom's proficiency on set pieces. The Gunners were anything but as the Baggies netted two goals off corner kicks en route to a 3-1 victory that was Arsenal's fourth defeat in five league matches and sixth in nine spanning all competitions.
Even the wins in this span are little to crow about given they came against relegation-threatened Hull City and fifth-tier sides Sutton United and Lincoln City. This wretched run of form has turned nearly all public sentiment against Wenger, who only seems to antagonise the fan base further when he refuses to publicly address the elephant in the room.
It is common knowledge Wenger has a two-year extension on the table from Arsenal to potentially return for a 22nd season, and for the man who said he made up his mind on his future following the loss to West Brom, his refusal to provide the ultimate answer at every press conference has bordered on torturous to nearly everyone but himself.
"I've always been very clear in my mind," Wenger said. "I will remain like that. I think it's a subject that at the moment is not sorted completely out. I have nothing more to add to that. … But anyway, do I stay two months or two years? My commitment will be exactly the same. The time I spent here does not influence my attitude at all."
Wenger deflected questions on what needed to be "sorted out," but as a team, the futures of Alexis Sanchez and Mesut Ozil are at the forefront of things that need such attention. Both have contracts that expire following next season and both had have talks for extensions stall before the run-in, leading to rampant speculation regarding their future.
Whether their fates are entwined with Wenger's decision is unknown, but after Sanchez expressed his desire to stay in London to the Chilean press, the Frenchman expressed the belief he will be able to retain the South American forward's services.
"I hope he will stay at the club. He was right to be cautious," Wenger said without a hint of agitation. "When people give interviews in their home countries the interpretation is not what it's always what he wanted to say. I don't see anything negative in what he said. He wants to win the Champions League. I understand completely what he says."
The biggest news on the pitch for Arsenal will be goalkeeper David Ospina starting in place of the injured Petr Cech, who will miss both this contest and Wednesday's London derby at home versus West Ham United. Influential holding midfielder Santi Corzola has been ruled out for the rest of the season with an ankle injury, depriving Arsenal of a vital piece as they try to overcome a six-point deficit and their current sixth-place standing to claim fourth in the table.
While City are in better standing - they enter the weekend two points behind Tottenham for second and are one better than Liverpool for fourth - a victory here would prove not only added security of a top-four finish but also the validation the side have lacked as they try to build themselves in the mold of Barcelona and Real Madrid and Bayern Munich as one of the continent's best.
Like Arsenal, there have been fits and spurts at times as Guardiola has constantly tinkered with his formation and personnel to find out what works, what doesn't work, and in the case of a large-spending club, where he needs to spend money to address shortcomings and add depth.
The Citizens are unbeaten in their last seven league matches (4-3-0) but went into the break on consecutive home draws, first in a turgid scoreless encounter with Stoke City and then a livelier 1-1 stalemate versus Liverpool.
Sergio Aguero provided the point with a goal in the 69th minute to cancel out ex-City midfielder James Milner's penalty, the end game following a shrewd substitution by Guardiola that saw Bacary Sagna replace Yaya Toure to reshift the midfield. It may have been only one point, but for Guardiola, it was a touchpoint to what he wants Manchester City to be.
"The spirit, how we played, it is one of my happiest days as a manager," he told City's official website. "We created more than them. We created more chances than Liverpool today but we just couldn't score. To achieve the big targets you need to be clinical."
This is a big week for City, who will continue their London adventures with a midweek clash at table-topping Chelsea. With the Blues ahead 12 points and almost out of sight in the table, the focus has turned to consistent play in the run-in and their first potential FA Cup title since 2011 as they face Arsenal in the semis at Wembley later in April.
"We face lots of games - lots of very important games that will define our season," midfielder Aleix Garcia said to City's official website. "From the beginning of the season, we have all the trophies in our minds. Winning the Premier League is difficult and we are out of the Champions League, so the FA Cup is probably the best chance we have this season.
"This team is ready to win it and this is what we want. We will fight to win it."
Aguero has four goals and an assist in nine lifetime matches versus Arsenal, while Walcott, who provided an early lead for the Gunners in the reverse fixture in December, has four goals in 13 contests versus the Mancunians.
The teams have split their last 10 league matches, claiming three victories apiece while sharing points the other four occasions. Including his stints at Barcelona and Bayern Munich, Guardiola is 5-2-2 lifetime versus Wenger and Arsenal.