Fikayo Tomori couldn't have made a better decision than leaving Chelsea in January.Despite making 22 appearances for the Blues last season and picking up his first England cap, the young defender was essentially exiled from Frank Lampard's squad for the 2020/21 campaign.It's remarkable to think that Tomori was only afforded 45 minutes of Premier League football this season when Chelsea looked to have one of the division's wobbliest defences at times.

Tomori loaned out to AC Milan

Speaking to the Telegraph, Tomori explained his confusion at the situation, admitting: "I don't know what happened, it wasn't really explained to me.

"I was suddenly out of the squad and I don't really know why. It was so frustrating."

However, Tomori's decision to seek a loan exit in the January transfer window proved to be an inspired one and it said everything about his quality that it was AC Milan who came calling.

Man Utd vs AC Milan

Yes, the Rossoneri aren't the Champions League challengers of old, but they are locked in a fierce fight for the Scudetto and have a much better squad than that of the Chelsea reserves.

As such, you can't help feeling as though the Blues have been left with egg on their face as the young Englishman has already doubled his 2020/21 appearances since moving to the San Siro.

And English football was given a clear reminder of Tomori's class when he returned to the land of the Premier League for a Europa League round of 16 clash with Manchester United.

In the end, the spoils were shared at Old Trafford with Simon Kjær cancelling out Amad Diallo's first goal for the club at the death, though Tomori still found time to make an impression along the way.

Tomori's heroic battle with Greenwood

That's because a fantastic clip of the Chelsea loanee has been doing the rounds on social media, highlighting his ability to deal with a fellow Three Lions starlet: Mason Greenwood.

In a situation that looked for all intents and purposes to have mugged off Tomori, the Milan enforcer proceeded to show fantastic pace and composure to regain the ball with a heroic tackle.

Marry that to some impudent footwork once Milan had regained possession and it couldn't have been a finer demonstration of why Chelsea should fight to keep him on their books. Check it out:

Talk about some brilliant old-fashioned defending.

Chelsea have made a mistake

You'd be forgiven for thinking that Chelsea have seriously dropped the ball here because according to Goal, AC Milan have a purchase option on Tomori for the relatively-small fee of £21.5 million.

Now, sure, Chelsea have ironed out most of their defensive woes under Thomas Tuchel, but seeing a defender with as much potential as Tomori potentially leave so easily would be a massive blow.

Thiago Silva is surely only going to spend another season at Stamford Bridge at most, so it's not from without the realms of possibility that Tomori would still have become a Chelsea starter.

I'm sure Andreas Christensen, Antonio Rudiger and Kurt Zouma will have something to say about that, but it's not as though Tomori is impressing for a random club in a weak European league.

No, we're talking about a team six points shy of the Serie A summit and above Cristiano Ronaldo's Juventus, carrying an away goal back to San Siro with a very real possibility of eliminating United.

If that's not enough to make Chelsea realise that they've made a mistake, then we don't know what is. They'll just have to keep their fingers crossed that Milan want to keep their wallet shut.