Raul Garcia's first-half header proved the difference at the Mestalla and Pizzi has claimed that his side 'fell into Atletico's trap' in the La Liga clash.
"Atletico do something very similar to Sevilla. They are teams that are comfortable playing with a lot of personality and intensity and you can't ignore these factors," Pizzi told reporters.
"They are important in football, as we have seen in the past two games.
"You can see the match developing as it did against Atletico and I am very critical of myself and my players. We fell into their trap. In the second half we were very exposed. They had more attackers, ran faster, are bigger and deserved to win."
Valencia face Sevilla in the second leg of their Europa League semi-final on Thursday trailing 2-0 from the first leg last week.