Spurs needed to score in Italy after a 1-1 draw in the first leg of their last-32 tie in White Hart Lane, but Fiorentina broke the deadlock in the 54th minute.
You only deserve to go through to the next round if you score and they scored more goals than us
Germany international Mario Gomez broke the deadlock before on-loan Chelsea forward Mohamed Salah sealed the Serie A outfit’s place in Friday’s last-16 draw.
Tottenham face Premier League leaders Chelsea in the League Cup final on Sunday, and Pochettino warned Spurs that they can’t dwell on their Europa League defeat.
“This one was the first final for us and all players are disappointed, but now we need to look forwards, to recover quickly, because on Sunday we have another game,” Pochettino said. “It is impossible to change the game now.
“It is true that it was key, this action. You need some luck to score sometimes if you are to win the games.
“It is true that the second half we made some mistakes and we take a risk and Fiorentina scored.
“We did not score and, if we want to analyse the game, it is easy: Fiorentina scored, we didn’t score and in football you don’t score it is difficult to win games.
“I think they scored more than us and we didn’t score. If we analyse the performance, we played very well again but didn’t score in the first half.
“You only deserve to go through to the next round if you score and they scored more goals than us.”
Pochettino opted to rest free-scoring Harry Kane and midfielder Ryan Mason for the clash against Fiorentina ahead of the Capital One Cup showpiece.
Kane, who has scored 22 goals in all competitions this season, came on as a second-half substitute but the striker was unable to make a difference.
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