Jose Mourinho's side failed to win a trophy this season after falling short in the Premier League title race, and Schurrle believes that it was their inability to produce their best against teams in the bottom half of the table which eventually cost them later in the campaign.
"We didn't play well against the teams lower in the table," the German told reporters. "That's where we lost it. We need to be ruthless in these matches, to be strong, and then they will have no chance.
"They will see when we come on the pitch that we have the will to win and they will see they don't have a chance against us. We need to leave no doubts.
"That is what we had in many matches last season. Even when we won it was not always clear. That's what we need to change next season."
Chelsea finished third in the Premier League, and were knocked out of the Champions League at the semi-final stage by Atletico Madrid.