Despite this, Lewandowski did not appear to be the best rated player of the game but he was the worst rated player based on the aiscore. Kounde and De Jong were the two players who had the highest ratings in that match, but I agree that overall Barcelona didn't perform as good as expected in that match.
Lewandowksi isn't good like his was, I think his performance is declining in this season. If Joao Felix can show a good performance, I believe Barcelona will sign him to replace Lewandowski's position.
Osasuna is really good in counter attack, they can maximize their chance to score a goal. While Barcelona only keep passing in order to make them looks more dominant and giving pressure to Osasuna.
Lewandowski is 35 years old now however I still don't want to show this as an excuse for him. Because we have all seen what Benzema did at this age before leaving.

I'm curious about whether things would have been more different if Lewandowski was still playing for Bayern Munich now.
Because since he joined Barcelona we can't watch the same level of scoring productivity. It is early for this season maybe but who knows he might score goals even less than the previous season. Felix would still not be their first choice though as long as Lewandowski doesn't have really serious problems.