A lot has been said and written about the signings Diego Simeone and co. made in both the summer and winter windows, but the two-legged tie with Liverpool in the Champions League marked a turning point.
This is due to the fact we got to see the best versions of summer signings Renan Lodi, Joao Felix and Marcos Llorente.
It was Llorente who scored two famous goals at Anfield to knock the Reds out of Europe earlier than the final for the first time in two seasons, and it brought to an end a period where he hadn't really been able to find a regular place in the team.
There were eight new faces arriving at the club over the two aforementioned windows, and only Yannick Carrasco hasn't really had the time to be judged yet.
Kieran Trippier and Felipe are two other fresh signings, but they have been among Atleti's most consistent performers in 2019/20, with the club getting fantastic value for money for the pair.
The bigger concerns were over Felix and Lodi, with the former being tasked with replacing Antoine Griezmann's contributions despite having had just one solitary season with Benfica's senior team.
The Portuguese playmaker also arrived with a price-tag of over 120 million euros, something which has only increased the scrutiny on him since he arrived.
Whilst a slender boy of just 20, Felix had taken to his task in Madrid with diligence, but he hadn't been able to show anywhere near the quality expected by fans.
That was until the trip to Liverpool, when he started to showcase his deft touches, his clever passing and an innate ability to find space in the final third.
Lodi, meanwhile, was able to keep both Mohamed Salah and Trent Alexander-Arnold quiet and was defensively solid in a way that Simeone had hoped would be possible when he brought the Brazilian in.
Source: m.allfootballapp.com