Heading into Christmas, all appeared well at Peter Bosz's Leverkusen. Top of the table and leading 1-0 against Bayern Munich, a return to Champions League football looked certain to return to the Bay Arena.

Yet two Robert Lewandowski goals at the end of each half turned the game around. And with that result, Leverkusen's season went into free fall.

Leverkusen have won just three Bundesliga matches in their 13 since that last-minute loss. Together with a limp surrender to Young Boys in the Europa League and an embarrassing defeat to fourth-tier Rot-Weiss Essen in the German Cup, that form saw Bosz cut loose.

"After an objective and very open analysis of the sporting situation, we agreed to make a cut," team manager Rudi Völler said.

"It could no longer be avoided."

Consecutive losses to relegation candidates Arminia Bielefeld and Hertha Berlin convinced management that Bosz could no longer turn this season around.

Troubles at both ends

While Leverkusen's defense will undoubtedly come under question once again - it's been a problem for the club for close to a decade - Leverkusen's demise has as much to do with their faltering attack.

They'd scored 27 goals in their first 13 matches, but have managed just 16 in their last 14 games.

Bosz's style of football will always leave gaping holes at the back, though he relies on his teams' attacking bravado to counterweight those deficiencies. When you have a porous defense and a misfiring attack, the gameplan has to be questioned.

Injuries to key defensive players such as Lars and Sven Bender, Lukas Hradecky, and Julian Baumgartlinger made life difficult for Bosz. But his tendency to name just one holding midfielder in an attacking 4-3-3 formation also continued to baffle amid poor results.

Leverkusen boast a plethora of attacking talents and reinforcements will only be necessary if one or two depart at the end of the campaign. Otherwise, defensive signings are a must in the off-season.

New hope?

Management, however, appears determined to continue the club's obsession with attacking football in hiring 39-year-old Hannes Wolf.

"We want to turn things around and take the path to success," sporting director Simon Rolfes said.

"Hannes stands for the kind of football we want to play - intense, offensive, aggressive, attractive."

It sounds very much like Bosz 2.0. Wolf is a very highly-rated young coach, but he has a patchy record so far in his fledgling career.

He got VfB Stuttgart promoted before he was harshly dismissed halfway through his first Bundesliga season with the club three points above the drop zone.

His next opportunity was bringing Hamburg back into the Bundesliga, a task he looked on course to manage with ease before an eight-game winless run saw them miss out on even a playoff spot. A short spell with Genk in Belgium was also underwhelming.

Wolf now has eight games to not only ensure Leverkusen qualify for Europe, but to also convince management he deserves a contract beyond the end of the season. He'll at least be able to count on the experience of co-coach Peter Hermann, who returns to the club he has a 29-year association with.

Leverkusen currently sit in sixth place, which should be enough for Europa League qualification. Champions League football appears unlikely, however, given they sit seven points adrift of fourth place.

Short-term gamble

Leverkusen have long held high ambitions to cement themselves with Champions League football. And given the quality within the squad, it's an appropriate target.

Bosz failed at the final hurdle last season, finishing 5th after dropping vital points against Hertha and Schalke. A second failure has not been forgiven.

Yet if Leverkusen are to establish themselves as Champions League regulars, following an attacking ethos blindly doesn't appear a wise long-term strategy.

Wolf will have to show off his acumen in defense, even though it doesn't feature on his job description. And if he's given a long-term contract, he'll need defensive reinforcements to fix a problem that predates Bosz by years.