Ancelotti of course had become Everton manager in a spectacular coup for the club just a month earlier when Branthwaite moved from Carlise to Goodison Park in January 2020, becoming the new coaches' first addition.
The 18-year-old centre-back was very much in the mold of player that then Director of Football Marcel Brands wanted and so in truth he was more the Dutchman's signing than Ancelotti's.
At the time Branthwaite was a teenager with great potential and understandably it took him a while to settle in on Merseyside after his move.
He had only played a few sporadic games with mixed performances for the Toffees by the time Ancelotti and his successor Rafa Benitez had both come and gone. And the jury was still out on him with his next manager Frank Lampard not particularly keen either.
Then last season, Branthwaite went over to Holland and he enjoyed a superb time on loan with PSV Eindhoven after forcing his way into the team, winning the Dutch Cup by the end of the campaign.
Then in the summer he went on to to feature for England's Under-21 European Championship winning team under former Everton midfielder Lee Carsley.
After that breakthrough time abroad (and PSV were keen to turn his loan into a permanent deal) Branthwaite looked likely to be back sitting on the bench most of the time under current Blues boss Sean Dyche as he turned to his old Burnley pair of James Tarkowski and Micheal Keane.
But several matches in and after a terrible 4-0 drubbing at the hands of Aston Villa, Keane was finally dropped and Branthwaite got another chance in the first-team.
Since then the now 21-year-old has been a revelation showing a superb combination of defensive strength, intelligence and tremendous maturity. Full England honours surely can't be long in coming.
Branthwaite's consistent excellence has not gone unnoticed and there were rumours earlier in the season that Premier League clubs were tracking him.
Now, arguably the biggest club in the World Real Madrid might be joining those admirers with today's reports that Ancelotti's current employers are looking at him, possibly with a view to making a bid in the summer.
The young centre-half penned a new contract just a few months ago and so any club that wants to sign him will have to dig deep.
I've said before that I think Everton must do all they can to resist any suitors for their star central defender. But a serious bid from the fourteen times European champions could be hard to resist.