Ralf Rangnick will have plenty on his plate once his appointment as Manchester United interim manager is confirmed.
On top of having to implement an entirely new brand of football, helping choose the club's next permanent boss and being given the small task of getting results back on track, the acclaimed German coach will need to make a U-turn on his personal views.
Although Rangnick must assess the Red Devils' entire squad, Cristiano Ronaldo is his outstanding conundrum.
Unwilling to press, on the wrong side of 35 years old and holding up a host of young attackers behind him in the pecking order, the five-time Ballon d'Or winner is far from Rangnick's type.
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However, the 63-year-old gaffer - renowned for his focus on intense pressing and getting players to run relentlessly - won't simply be able to boot Ronaldo out.
Back in 2016, Rangnick was asked if he would sign Ronaldo or rival Lionel Messi at former employers RB Leipzig, responding with a cutting answer.
"It would be absurd to think that it could work with them here," he stated.
"They are both too old and too expensive."
Fast froward to 2021 and Rangnick will have to find a way of incorporating the supreme goalscorer into his high octane system.
And it's unlikely that Ronaldo would start busting a gut the moment his manager tells him to.
The 36-year-old has acknowledged that he has to conserve energy in matches, as opposed to pressing like most top forwards such as Mohamed Salah and Bernardo Silva.
"I know when the team needs my help defensively," he told Sky Sports in October.
"But my role in the club is to win, help the team to win and to score goals - [the defensive side] is part of my job."
And he's certainly stubborn when it comes to his own rigid style of play, something he received criticism for at Juventus which has increased tenfold in the Premier League.
"The people who don't want to see that is because they don't like me but to be honest I'm 36, I win everything so am I going to be worried about the people who say bad things about me?
"I sleep good at night. I go to my bed with my conscience very good.
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"Keep going with that because I will still close mouths and win things."
Rangnick isn't even officially in the job yet but Ronaldo's mind must be ticking about what sort of things the 'Godfather of Gegenpressing' will demand of him.
Both may be strong-headed individuals but with CR7's clout at the club, his new boss - steadfast in his contemporary approach to football - might have to be the one change to the suit one of the all-time greats.