Pablo Sarabia gave his thoughts to the media after defeat at the hands of FC Barcelona at the Camp Nou.
Sevilla fell to first half goals from Luis Suárez and a Lionel Messi double before, and Sarabia believes the team were not on the pace in the first 45 minutes.
He said: "In the first half we weren't at the level and errors with the ball cost us dearly. All we could do was work and correct our errors."
The 24-year-old highlighted the team's improvement in the second half, even with the game out of reach by that stage.
He explained: "We improved in the second half but the broader picture is what it is and we have to improve. We can't lose balls so easily because it leaves us with lots to do.
"The dynamic is not good, but we have to go forward together and turn this situation around with that mentality."