I think people are sleeping on Atletico Madrid this season, they have a solid squad and a great coach, they could make a deep run in the UCL, especially if they can get their defense clicking properly.
Their defense usually is clicking properly as it is by far the best in La Liga. This goal fest against Barcelona was more like an exception, but that counts for both teams. 4-4 was crazy.
Atletico may have the strongest team to play against in the Champions League assuming that Real Madrid can pitch all their best players. Though Atletico has their home advantage in the second match and everyone who knows Atletico well also knows that playing against them in the second game in the Wanda Metropolitano is no fun. The fans together with Simeone is like a 12th player and the pressure for the referees is unbelievable. Going to be a nice round of 16.