Los Rojiblancos won 1-0 at Dinamo Zagreb in the Champions League on Tuesday but, despite enjoying almost three quarters of the possession, they only had Samir Nasri's first-half strike to show for their efforts.
Although they currently sit level at the top of Group H alongside Juventus and are likely to go through, Sampaoli says he is concerned about Sevilla's chances of progressing in the knockout rounds if they do not find a more potent cutting edge.
"When you play Champions League, however, you must score more goals and be more efficient when you have the chances," he told UEFA's official website.
"That's vital. It's in our hands to qualify in the fourth match if things go our way on the next matchday.
"I expect we will improve our finishing as we would have some problems against stronger teams."