Bayern Munich head into Wednesday night's Champions League match against Celtic without the injured Manuel Neuer, Frank Ribery and Juan Bernat. On top of that, the most important player in Jupp Heynckes' system is missing too: Javi Martinez can't play due a shoulder injury.
To understand the 29-year-old's relevance we have to go back five years. It's easily forgotten now that Heynckes very nearly lost his job after finishing as runners-up in all three competitions in 2011-12, including a chaotic "home" defeat by Chelsea in the Champions League final. After much deliberation, the board decided that changes were necessary but not on the bench. The veteran coach was retained while the squad was strengthened in key areas, and the incredibly driven Matthias Sammer replaced Christian Nerlinger as sporting director.
The new arrivals on the pitch -- defender Dante, striker Mario Mandzukic and holding midfielder Martinez -- enabled Bayern to play a much more aggressive, pro-active game to close the gap on Jurgen Klopp's trailblazing Borussia Dortmund.
Out of the new recruits, the Spain international was undoubtedly the most influential. By protecting the space behind Bastian Schweinsteiger and in front of the two centre-backs, almost like a sweeper, Martinez gave the rest of the team licence to hunt down the ball much further away from their own goal. As Sammer explained a few months ago, "the new-found stability at the back freed up energy to press more systematically at the other end."
Before the Champions League final between the two sides, Klopp complained that the Bavarians had stolen his tactics, but Bayern arrived at the same destination by taking the opposite route to his Black and Yellows. Dortmund's defence was solid because the pressing worked so well. For Bayern, it was the other way around.
A couple of crunching tackles by Martinez in the second half of the final at Wembley helped Bayern disrupt the flow of a rampant Dortmund team and put them on course for their Treble victory. Pep Guardiola, who replaced Heynckes as coach at the end of that season, didn't see the need for a purely defensive midfielder, however, at least not in that position. Martinez was earmarked as the central of three defenders at the back but injury problems saw his influence his diminish. Carlo Ancelotti played him as a centre-back, with mixed results.
It came as no surprise that Heynckes' first significant move after taking over at Bayern for a fourth time was to re-install Martinez as a Wellenbrecher (breaker of the waves) in the 5-0 win against Freiburg on Saturday. The calibre of the opposition was such that a more offensive line-up might have worked just as well, but the Basque's inclusion is an article of faith for the 72-year-old coach, his alter ego on the pitch, if you will.
Just as Heynckes is supposed to bring tranquility to a club beset by tension and disagreement, Martinez's role is to be the glue that holds the various disparate parts of the team together. The new-old manager's affable, approachable style has already led to a marked change in the club's emotional atmosphere -- everyone's a lot happier, it's fair to say -- but Bayern's ability to fulfill their ambitions will to a large extent depend on Martinez successfully reprising his job as the team's shock absorber.
Against Brendan Rodgers' Celtic at the Allianz Arena, the hosts are confident that the central midfielder's absence won't be too noticeable. Nevertheless, it'll be instructive to see how Heynckes compensates for the loss of the key man in his starting XI.
Because of Bayern's dominance in possession during the Guardiola years and his preference for deep-lying registas, the need for a Martinez back-up had never arisen. Consequently, Heynckes' won't find a like-for-like replacement. Corentin Tolisso is box-to-box, Thiago a playmaker, Sebastian Rudy a traffic director. Arturo Vidal's aggression and ball-winning skills would make him the most natural candidate to play in front of the defence but, then again, his all-round ill-discipline will trouble Heynckes. What you gain from Vidal's ability to burst forward, you lose by his inability to keep his head and his position.
It's a conundrum that might not prove impossible to solve at home to the Scottish champions, whose problems on the road are well documented. Celtic have lost 26 of their 31 away games in the Champions League, a 3-0 win at Anderlecht last time out notwithstanding. But Martinez's absence will still prove an early, formidable challenge for Heynckes in his latest stint. Hailed as a peacemaker after a few days in charge, he now needs to show that he can bring balance to Bayern's game even when Martinez is not available.