Klopp admitted that he has been left wondering what might have been had he had a full squad to choose from throughout the campaign, with his side currently sat nine points behind league leaders Chelsea.
"I think we can all agree that if we could have played our first 12 or 13 for the whole season, and we are only six, seven, eight points away from the very interesting region of the table, then it's not unlikely that it could have worked," the German told Sky Sports News.
"But it's not important now because we don't know for sure. It's not allowed to look back. We have to find a line-up solution for the next game.
"What I can say is that we really need all our passion in a situation like this. I said a few days ago that it's not about playing the best football, it's about getting results. Most of the time it works if we've got a good plan but the passion is really important.
"We need all the passion from the stands. It's Anfield. We've had two away games. It feels like we last played here eight weeks ago or something, but it was only two or three weeks. Now we are back."