In the earlier part of the 2011/12 season under new manager Andre Villas-Boas, there was not much for Chelsea supporters to smile about.
The Portuguese coach was struggling to implement his philosophy, resulting in inconsistent results and performances, while his decision to freeze out big names damaged his relationship with the Stamford Bridge faithful.
Amid all of that, though, there was at least one positive from Villas-Boas’ reign, which came in the form of Juan Mata.
Signed for £24.03m (Transfermarkt) from Valencia in the summer of 2011 Mata quickly became a fan favourite at the Bridge.
As an attacking midfielder, the 30-year-old did everything a coach would expect from a player playing in that position at this level.
There, Mata scored goals, created them and was just an overall threat in virtually every Chelsea attack.
The Spaniard’s set pieces were not too bad either. It was his corner, of course, that Didier Drogba got on the end of to score the equaliser in the Blues’ famous 2012 Champions League final triumph over Bayern Munich.
That alone arguably made Mata worth the £24m Chelsea paid. The season after, however, was when the Spain international truly showed what a bargain his side had picked up.
On Chelsea’s way to a third-place finish in the Premier League and winning the 2013 Europa League, Mata scored 19 goals and assisted an incredible 35 in all competitions (Transfermarkt).
A lot is said about Chelsea getting rid of the likes of Kevin De Bruyne and Mohamed Salah. But by selling Mata to Manchester United, they lost an equally talented player.