Xabi Alonso's unbeaten Bundesliga leaders are set to face an Eintracht Frankfurt side that recently ended Bayern Munich's undefeated run in the German top flight. bundesliga.com assesses the key factors that could tip the balance in the Matchday 15 encounter...
Tacticians at the ready
An intriguing contest will be overseen by a couple of coaches whose respective attention to detail an in-game instructions will set the tone for this Matchday 15 encounter.
Alonso's side have been purring as a collective unit with a togetherness and morale among the squad that is second to none. The Spaniard highlighted the club's shrewd dealings in the transfer market of late along with his on-field leaders - like Granit Xhaka - as part of Leverkusen's incredible success this term.
Yet it is also Alonso's footballing masterplan that has helped to make the Werkself one of the most attractive sides in Europe these days and a nightmare for opponents to play against. Pinning opposing teams back in the final third with some slick attacking interplay while also offering plenty of threat from wide positions and on the counter-attack mark Alonso's outfit out as a well-oiled machine, with each player certain of their role.
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The 43-year-old, who started at the Eintracht helm only last June, took over from Oliver Glasner and is clearly eager to repeat the some of the Austrian's success in Frankfurt. His Eintracht side are still taking shape, with last weekend's Bayern success was the side's first victory after a run of five winless games. Yet the manner in which his team picked apart the reigning Bundesliga champions with a tactical masterclass suggests that Eintracht may have rediscovered the form that previously saw them go unbeaten in their opening nine matches under Toppmöller, a run that was almost emulated between October and November when Die Adler went eight without loss in all competitions.
Among Toppmöller's tasks this weekend will be to plan without suspended forward Omar Marmoush, who has scored seven times and laid on three assists in the Bundesliga this term. Whether or not the former Bayern assistant opts to stifle his counterpart with another variation on his tactical set up - which worked to perfection on his former side on Matchday 14 - represents one more eagerly awaited aspect of Sunday's game, but Toppmöller has shown he is more than up to the task of outwitting formidable opponents.
Watch: How Frankfurt beat Bayern Munich
A huge question facing visiting Eintracht is just how they will handle Bayer's brilliant wide players Jeremie Frimpong and Alex Grimaldo. Both players are on fire this term in a Leverkusen side that is unbeaten in 23 competitive games. Incredibly, the pair have added a combined 20 goal involvements to the Leverkusen cause, with Grimaldo scoring a head-spinning seven times to Frimpong's four. With a game that might be expected to be a tight affair, both Leverkusen's flying full-backs are capable of making a telling difference.
Against Bayern last weekend, Eintracht opted to feature Willian Pacho and Aurélio Buta on the flanks while Éric Junior Dina Ebimbe and Ansgar Knauff also put in a shift in helping to frustrate the Bavarian giants, and not just with their goals. If Frankfurt are to gain what would be another big scalp at the BayArena, all four players - should they be selected - will have to be at their very best once again to prevent Leverkusen's wide assault.
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Will it be a case of no Marmoush, no problem for the Eagles in Leverkusen? It's impossible to imagine that Sunday's visitors will fail to miss the Egyptian, who - as previously mentioned - has weighed in with 10 goal involvements in his 14 Bundesliga games this season. The striking role could well be bestowed upon Jessic Ngankam, who has yet to find the net in 11 top-flight outings this term.
The responsibility on supporting attackers Farès Chaïbi and Knauff will thus be ratcheted up several notches. Chaïbi's two goals and six assists in 18 appearances across all competitions for Eintracht since a summer move from Toulouse have marked the Algerian international out as a serious threat whenever he takes to the field. His teammate Knauff, who scored his third Bundesliga goal of the season in the 5-1 demolition of Bayern, will be in for a sweat-inducing game with several tasks to complete - but the 21-year-old's energy levels have never been in question.
Watch: Eintracht simply irresistible against Bayern
Leverkusen's forward organisation is far more straightforward, meaning the hosts should have a significant edge in this aspect of the game. The team's leading scorer with eight goals, Victor Boniface, has also provided six assists in his maiden Bundesliga campaign so far and in the Nigerian striker, Alonso has a powerful asset. Ably complemented by the mercurial Florian Wirtz and Jonas Hofmann in the latter third, Leverkusen will take some stopping in front of their home fans.
History favours Leverkusen
Bayer have now been unbeaten in their opening 14 Bundesliga matches on three occasions. Interestingly, on one of those, Toppmöller's father, Klaus, was in charge at the BayArena in 2001/02. Former Bayern boss Jupp Heynckes was the man at the Bayer helm when the side from North Rhine-Westphalia matched the current feat of 14 games unbeaten back in 2009/10.
If Eintracht are to topple their opponents this weekend, they will need end a sorry sequence of results at the home of the Werkself. Leverkusen have won their last eight home meetings against the Eagles, while Sunday's hosts have also been victorious more times (23) against Frankfurt at home than against any other Bundesliga team. Added to the B04 incentives to pick up another three points in what has already been a memorable campaign is the fact that Alonso's men can be crowned nominal 'autumm champions' with victory.
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