The biggest problem with Lewandowski has rather been to have a difficulty in scoring goals in big games in the Champions League. I watched him waste so many opportunities against big teams there which cost them high in the group stage later. I don't want to put the blame on only him of course don't get me wrong about that. The team effort was also inadequate in such games.
But in this season Xavi will be expected to do better in general as I said. Not only the team effort but also Lewandowski should make a big improvement in their performance in the Champions League. This level is still enough for the La Liga title but enough to be more successful in the Champions League.
Lewandowski is a great striker but even a great striker could have bad days and he is also getting older as well so even though he has a high technique, that doesn't stop his body from failing time to time. That's when players start to realize they should retire, he should not just yet, because he is still great at the league level, but his body doesn't do what his brain tells him to do anymore, but of course just tiny situations we see in huge games, otherwise he is not that bad.
We have seen Barcelona got eliminated by Inter and Bayern, which were great teams, Bayern is great as we all know and Inter lost only on Finals, so that shows that it wasn't really as bad as people think it was and we shouldn't be shocked about it.