The Reds have a precious away goal from last week’s 1-1 draw in Germany, given to them by Divock Origi and Klopp’s main dilemma appears to be whether to start with the young Belgium international, England striker Daniel Sturridge or, less likely, play both.
Origi came off the bench to score twice in Sunday’s 4-1 win over Stoke in which Sturridge, who started, also scored.
“If all players play like this then I have to make hard decisions,” Klopp told liverpoolfc.com.
“That’s not my hobby but that’s the best thing to do as a manager and hopefully we have to make hard decisions for Thursday.
“That’s a good thing if I have to think about the line-up or something. That’s what I do most of the time, to be honest.”
Vice-captain James Milner, who will lead the side in the absence of the injured Jordan Henderson who has been ruled out for the remainder of the season, has called on Anfield’s fans to help them get over the line against the tournament favourites.
“Any player wants to play in the big games and the best atmospheres [and] European nights at Anfield are definitely right up there with anywhere on the planet,” he said.
“That’s going to be massively important for us no matter what happens.
“Even if the worst happens and they get an early goal, [the fans] can roar us on to get back into the game.
“We managed to nullify their fans – which is a great atmosphere as well – and got a good result. Hopefully we can use our atmosphere.
“There are a lot of experienced players in there and they are used to playing in front of the Dortmund crowd and other big games so I think they’ll probably be used to it.
“It can probably help us more than it can damage them.
“The fans are always brilliant and hopefully it’s another special European night.”