The Reds stunned their Portuguese opponents with a 5-0 victory in the first leg of their last-16.
But the German has said he will not be taking the fixture lightly, despite having a pivotal clash with Manchester United just four days later.
"Arsenal for example, that's so unfair. They were through in the tie and had a final on Sunday yet I only hear after the game things like, 'wow that was embarrassing against a Swedish team'. But they are through in the tie and played a final on Sunday.
"That's the situation. We play Man United, we will not rest anybody. We will play a strong side against Porto and a strong side against United."