Inter coach Stefano Pioli believes it is clear his side must continue to improve, despite their Europa League win over Sparta Prague on Thursday.
Ahead of the game at San Siro, Inter were already guaranteed to finish bottom of Group K, while their visitors had secured top spot.
However, Eder's brace fired the Serie A side to a 2-1 victory - with Pioli later reflecting on the positives alongside the areas in which his team must still get better.
"We tried to take the initiative, and we were focused, sharp and created some good situations," he told Sky Italia.
"Clearly, at the moment, we still need to improve. [We must] be quicker and more effective.
"We are seeking a more balanced outfit [with a 3-4-3 formation] that can be more efficient both defending and attacking. We'll see what system is the most effective.
"All it takes is a negative incident - which can happen, because we are not the best side in Italy and are recovering from a difficult situation - and everything becomes more difficult.
"When there's a setback we tend to lose our shape and get stretched out."
With their European campaign over, 10th-placed Inter can turn their attentions back to Serie A, where they host Genoa on Sunday.