Agreed, losing like that can be a huge blow to the team’s confidence. Atletico played well and kept Barcelona under control for most of the match, but the ending was a complete disaster. Barca once again showed their mentality and ability to turn games around—this is their second major comeback in a month. Atletico now has to find a way to rebuild their confidence quickly, or their season could unravel.
Although it might look funny, but it seems some of the teams that were knocked out of the UEFA champions league are having poor results. Liverpool have not been doing well since they were defeated by Real Madrid and they have lost an important game. Atletico Madrid also lost a game that almost everyone thought they had won. Maybe the disappointment or psychological effects of leaving one of the most prestigious trophies in Europe are too much to easily forget. I think the coach of ATM has so much work to do to revive the confidence of his boys. Undoubtedly it was an outstanding performance from Barcelona.
You should not be surprised seeing the teams knocked out of the UCL having poor results, remember that being eliminated from that apex competition can be very demoralizing. Teams like Liverpool had hopes that they will win the UCL this season but ending it the way they did can have a toll on their psychology and that is exactly what is happening. If they play one or two matches and maintain those poor result, I'm sure they will pick up and with the help of the management, they will bounce back stronger. Liverpool is just lucky that they are already many points away so these few drawbacks will not deny them the Premier League title this season.