The club chief is fully confident that the Spanish side will get through their group, despite earning just two points from their opening four La Liga games
The Andalusian outfit have been drawn against alongside Freiburg, Estoril and Slovan Liberec after being allowed into the competition, due Rayo Vallecano, who originally qualified, being denied a Uefa licence.
However, Del Nido is certain that his side will be able to make it out of the group stage and into the knockout phase of the competition.
"I have zero concerns about qualification," the 56-year-old told reporters.
"We have 14 new players, and it will take time for them all to learn the tactical and technical elements of [coach] Unai Emery's system. In a couple months we will be much better and will be losing less games."
Sevilla lost 3-2 to Barcelona last Saturday thanks to a last-second Alexis Sanchez winner and Del Nido is angry at the manner with which his team surrendered a point.
"After scoring in the 92nd minute we should've seen the game out and got a point," he continued.
"Instead we conceded in the 93rd minute, which I am still angry about. I understand that a lot of the players are young, but it was still frustrating."