Mario Gotze has already played his last game for Borussia Dortmund, having been ruled out of the final with a hamstring injury and agreed a transfer to rivals Bayern Munich in the summer transfer window.
His absence from the final will surely mean a starting spot for Kevin Grosskreutz, but where he plays is dependent on whether Klopp chooses 4-3-3 or 4-2-3-1. In the latter, the likeable Dortmund coach will be able to use two hard-working wingers on either flank, with Jakub Blaszczykowski full of powerful running down the right. With Grosskreutz on the left, Dortmund would have two players well-suited to the difficult task of tracking the forward runs of Phillip Lahm and David Alaba.
Much is said about Arjen Robben and Franck Ribery, but the attacking contribution of Bayern's full-backs should not be underestimated. Lahm ranks second for assists in the Bundesliga with eleven this season, while Alaba is less involved in build-up play, but still contributed an important goal (albeit deflected) in the quarter-final against Juventus.
Lahm's attacking bursts down the right are particularly dangerous - with Robben dragging the opposition full-back inside with his movement towards the penalty area, and Muller's tendency to drift towards his usual position on the right, Lahm's overlapping runs only exaggerate Bayern's bias down that flank. With Robben and Muller occupying the defence, his movement often goes unchecked, leaving him free to cut the ball back from the byline for the near-post run of Mario Mandzukic.
It sounds complicated, but it is a very basic attacking move, and it is important that the left-winger does not allow Lahm to have this freedom to get forward. Klopp has two options. He can play Reus on the left, as he is diligent enough to track back, and hope that Lahm plays more cautiously, given the counter-attacking threat of his opposite marker. Otherwise, Reus can play centrally - reprising his role at his former club, Borussia Monchengladbach - and Grosskreutz can play a disciplined role on the left flank.
The loss of Gotze might convince him to make a more cautious approach, as he has done previously against Bayern, with his side standing off more - and in a 4-3-3 formation, long periods without the ball will make them more of a 4-5-1.
With Bayern possessing great ball-playing midfielders, and the additional threat of the wide players, who will come inside towards the centre, Klopp might prefer to pack the centre - and could use Sebastian Kehl alongside Bender, with Gundogan higher up, to give Dortmund more physicality in midfield.