It will be Battle of the Balds at Wembley when Pep Guardiola meets Erik ten Hag on Saturday afternoon.
United have won the Carabao Cup in Ten Hag’s first season as manager, while Pep Guardiola has wrapped up the Premier League and wants the FA Cup and Champions League.
Only United have managed this in the Premier League, doing so memorably in 1999. City, though, have been steamrolling teams in recent months and Guardiola could match Sir Alex Ferguson if he wins all three.
Standing in his way is a man he once tipped to succeed him at the Etihad.
The two coaches worked together at Bayern Munich where Guardiola was head coach and Ten Hag was in charge of the reserve team.
The pair jostled with ideas and coaching methods for two years between 2013 and 2015 and Ten Hag left an impression on Guardiola.
Just weeks before Ten Hag was confirmed as the next United boss in 2022, Guardiola was asked if the Dutchman could succeed him on the other side of the city.
“Are you asking me if Erik Ten Hag could be here? Definitely.
“A lot could be here and I think he could be one of the ones. For the way he approaches the game, definitely, definitely. I will tell (director of football) Txiki (Begiristain) now!”
It was not a surprise to see Guardiola check out how Bayern’s B team was getting on during his time in Bavaria and was said to be often blown away by Ten Hag’s methods.
Eventually he became a manager in his own right and took over at Utrecht in 2015 before landing the Ajax job two years later where his famous side reached the Champions League semi-finals in 2019.
Matthijs de Ligt, Hakim Ziyech and Frenkie de Jong all earned mega moves out of their European campaign while Ten Hag became one of the world’s most coveted coaches.
Speaking about their time at Bayern, Guardiola said: “We spoke quite regularly and he is just an incredible person and human being.
“I was surprised at how humble he was.
“For his qualities, just take a look at his Ajax team in the last years.
“It is a joy to watch and in many games, not just the year they got to the Champions League semi-final – but with little details they would have reached that final.
“The relationship we had was good, especially when we talked about football and the second team, and with players he was exceptional.”
Once colleagues, now rivals – the two will fight it out for the FA Cup in their respective red and blue corners on Saturday.
Man City vs Man United in the 2023 FA Cup final is live on talkSPORT on Saturday 3 June from 3pm