Leverkusen vs. Dortmund: three key battles

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Leverkusen are the early season league leaders with an undefeated record of 11 wins and a draw from their 12 games so far. Dortmund, last season's runners-up, are 10 points back in fourth.

Xabi Alonso's side go into the game as betting favourites, but Die Schwarzgelben - who guaranteed progress to the UEFA Champions League knock-out rounds with a 3-1 victory over AC Milan on Tuesday - can never be written off.

bundesliga.com takes a closer look… 

1) 'Grim' prospect for any opponent

Victor Boniface has surpassed expectations since his summer arrival from Union SG, his seven Bundesliga goals making most fans forget about the groin injury that has ruled Patrik Schick out of the early part of the season.

But matching his goal haul is Álex Grimaldo - a left-back. Throw in his four assists and the summer acquisition from Benfica has had a direct goal-involvement every 98 minutes he has played in the German top flight. Whilst he also takes free-kicks, the recent Spain cap is at his most dangerous marauding up the left. Indeed, he is only loosely a left-back.

Watch: Grimaldo, a revelation for Alonso's Leverkusen

How Dortmund contain him will be key. Niklas Süle, with his deceptive top speed and average of five successful tackles per game, might have been the preferred option at right-back, but illness ruled him out of the Milan game and Julian Ryerson might get the nod.

The Norway international is a more attacking option than Süle, and would plausibly do a better job of keeping Grimaldo on the back foot, but with Bayer's usual formation a 3-4-2-1 with wing-backs, and Dortmund's a 4-2-3-1 without, the Leverkusen man almost has the upper hand by default. 

2) Brandt strategy

At the other end of the field, Julian Brandt will be crucial to Dortmund's chances of hitting back. The former Leverkusen star has been BVB's most potent attacking force this season with four goals and five assists despite having only the third-highest average position among their regular starters.

Watch: Analysing playmakers Brandt and Wirtz

Brandt's ability to drift between the lines make him difficult to pick up in the first place, and it almost goes without saying that Grimaldo's partner in wing-back crime Jeremie Frimpong will leave space in behind. Odilon Kossounou will have to stay disciplined on the right of Bayer's back three, resisting the temptation to underlap.

But Brandt can play off either foot, and variously occupy space on the left, right, or at No.10. It will be a team effort from his former employers to keep him from making and taking chances.

3) Midfield minefield

While Mats Hummels starts a significant number of Dortmund's attacks with his laser-sighted distribution from deep - not a particular strength of opposite number and fellow Germany international Jonathan Tah - Leverkusen's come from the heart of midfield, where Granit Xhaka has been another success story since a summer transfer, in his case from Arsenal.

Xhaka and Exequiel Palacios are a double pivot that will likely come up against Dortmund's own in Emre Can and Marcel Sabitzer. All four players can get involved in the more agricultural needs of the position, but the Werkself pair out-strip BVB's in their use of the ball.

Leverkusen and Dortmund have the second- and third-best average ball possessions this season with 57 and 56 per cent respectively (Bayern Munich lead the way with 60), but Alonso's side lead the way with 89.9 per cent of successful passes per game, which is 3.7 clear of fourth-best BVB.

Flashes of inspiration from Florian Wirtz and Marco Reus could decide the game at either end, but the above are three cornerstones that will be giving Alonso and his opposite number Edin Terzić sleepless nights between now and Sunday.