Athletico Madrid can't really challenge Real Madrid in the Champions League, but they can get the opportunity in the league or other trophies. When it comes to the Champions League, Real Madrid is always a different club and it's very difficult for any club to defeat them in the competition. Barcelona has more talented players than Athletico Madrid, and Barcelona usually defeats Barcelona in the La Liga, but this season was different because even Madrid hasn't yet won Athletico in the league, all there first and second leg are probably end in a draw, but Athletico Madrid get the chance and defeat Barcelona at home in the league fist leg, we don't know if they can still get the chance to do so in the next leg.
Madrid will face Athletico Madrid in the opening leg of the UCL next week, and I am confident that Madrid will do everything necessary to win at home because they are playing in Madrid first. And, once again, I believe that Athletico Madrid has never had the opportunity to defeat Real Madrid in the Champions League. This season madrid have crucial players on the team and am sure they can probably repeat the past and defeat Athletico Madrid in the first leg and second in the competition. Barcelona are facing Benfica and that game will be an easy win for Barcelona since Benfica are not excellent as Barcelona this season and probably Barcelona will qualify to the final this season in the ucl however we can't predict what will happen in the competition, but am in my opinion i think Barcelona are doing well currently and he show good quality that they will get to the final.
Madrid must do their best, they qualified for the last 16 with difficulty. Facing Atletico who are used to meeting I think they will not have difficulty reading the tactics that will be used. However, Atletico must also have some of the same thoughts to defeat the strategy that will be used by Madrid.
Maybe the match will be more exciting than the match against Man City.