Cala welcomes new signings
Last season Cala was called back from a loan spell with AEK Athens midway through the season following the departure of Martin Caceres to Juventus.
However, he believes the clubs needs to be stronger defensively to be able to finish amongst the best teams and qualify for European competitions.
“It would be naïve for me to think that Sevilla will not strengthen position,” Cala told reporters. “We need new players and we need competition.
“Sevilla has to be in Europe and we have to improve and do much better than we did last season.”
However, the 22-year-old believes the whole team has to work harder in that regard and not leave the entire responsibility to defenders.
“I guess we have to strengthen all lines of the team,” he said. “I think it's unfair to blame only four defenders for poor results.
“It’s not just the defenders who fail but it’s always a defensive system, which involves all players.”
Sevilla have also signed offensive players in attacking midfielder Javi Hervas and forward Bryan Rabello.