Only a few weeks ago, Bayer Leverkusen’s results vector was pointing so resolutely downward that there was talk of things being over for Roger in the cockpit, as experts queued up to explain that the dive down the table was all about Schmidt. The coach’s refusal to leave the pitch on the referee’s orders during the 1-0 home defeat to Dortmund in February had brought a three-week suspension in the league, two defeats and one draw, and a general loss in confidence that also saw the club knocked out of the Europa League. His system, dismissed as “brute pressing” by Die Zeit, lacked finesse, defensive balance and creativity, the critics sneered.

Bayer’s general manager, Jonas Boldt, was forced to deny that the 49-year-old was about to be shown the door at the BayArena. “We never considered parting ways with him,” he insisted last month. “When you see his passion day by day, his team talks, his practice sessions and the way he improves every player, we feel vindicated [in sticking with him].” The Leverkusen official did admit, however, that Schmidt had “made mistakes”, hinting at a level of stubbornness that didn’t help anyone.

All throughout the first half at the Veltins-Arena on Saturday, the well-known failings of Schmidt’s team were being brutally exposed by a Schalke team bursting with youthful zest. The Royal Blues scored two goals and even missed a penalty – Klaas-Jan Huntelaar failed from the spot for a fifth time in seven attempts – while the visitors were disorganised in the middle of the park, where Lars Bender’s lack of match sharpness was painfully obvious, open at the back and limp up front. In this key match between two Champions League contenders, Leverkusen were once again bottling it, Leverkusen-style.

But Schalke’s “appetite for self-destruction” (Der Spiegel) proved much bigger than Bayer’s. Schmidt calmly explained to his men during the break that André Breitenreiter’s side were always prone to “insecurity” and that the volatile mood of the crowd could work in Leverkusen’s favour as well.

And it did: as the rejigged visitors – Stefan Kiessling had come on as second striker and Kevin Kampl moved deeper to replace Bender – turned up the pace at the restart, Schalke inexplicably fell asleep. “We came over them like an intercity express,” said Bayer winger Julian Brandt, the scorer of the Anschlusstreffer (2-1, 54min).

Just 393 seconds later, Bayer had turned the result on its head with further goals from Karim Bellarabi (helped by Ralf Fährmann going down with all the agility of a railway gate, to stay with the train analogies) and the irrepressible Chicharito. Schalke did raise themselves for a final push at the very end but Bernd Leno in the Bayer goal thwarted a fierce Huntelaar shot from point blank range.

“We had the chances to kill the game off but didn’t take them,” said Schmidt, “so we had to make sure we didn’t concede another one.” The win, their sixth successive in the league, all but confirmed third place for them. Fourth-placed Hertha (beaten 2-0 by Bayern) are five points adrift and will probably be overtaken by Borussia Mönchengladbach (3-1 winners against Hoffenheim at home); Schalke are consigned to another season without the Champions League.

Süddeutsche Zeitung seemed unsure as to the extent of Schmidt’s role in Leverkusen’s return to the Bundesliga elite (“the quality of the team and that of the talent of young players such as Calhanoglu, Brandt, Wendell and Tah could be not be doubted, sensibly, but there was a lot of doubt about the sometimes cantankerous coach Schmidt,” wrote the broadsheet) but a second top-four finish in as many years for the trained engineer from Kierspe points at some serious managerial talent.

Leverkusen have always had decent squads thanks to their superlative scouting in South America and ability to poach German players close to greatness. At the same time, making a functioning team out of professionals who tend to regard the BayArena as a gateway to bigger and better clubs has been rather difficult. Schmidt’s blueprint of hard-running and pack-hunting was not perhaps the obvious fit for this technically gifted side. But it is one that has brought a sense of social cohesion and urgency, the odd chaotic spell within some games notwithstanding. Class: sometimes it shows in April.

On top of that, Schmidt has succeeded in creating real value, as far as his players are concerned. The elegant but lightweight Son Heung-min was happily offloaded for €30m to Spurs last summer after a strong campaign, and half the team would command similar transfer fees – if Premier League clubs are doing the buying – today. From relying on Kiessling’s goals and Calhanoglu’s dead-balls, Leverkusen have developed into a much more flexible side, with their own version of the BBC (Bellarabi, Brandt and Chicharito) tearing through opposition defences.

The latter has resurrected his career with 26 goals in 40 games, and the 19-year-old Brandt has found a consistency that is at last in tune with his ability. He has now scored in five consecutive games and is in contention for Germany’s Euro squad. “Will the baby-faced Brandt become Löw’s new Odonkor?” Die Welt asked on Monday, in memory of the World Cup 2006 supersub David Odonkor. Brandt’s a much better player than the former Dortmund winger – who’s now in charge of seventh-division TuS Dornberg – even if he’s not quite a household name just yet.

Bild, in what must rank as one of those “intensive research” exercises beloved by its columnist Alfred Draxler, ascertained that Brandt Zwieback and namesake Willy, the former West Germany chancellor, return more Google hits than the former Wolfsburg youth player. A few specious rumour-mill mentions will undoubtedly rectify that in no time at all.

For the Bundesliga’s sake, one must hope that Leverkusen will be able to keep their team together a little longer, to once again grow into a side that can realistically challenge for the title, as they did at the turn of the century.

In the Chilean midfielder Charles Aránguiz, they have certainly imported another superstar in the making. One wonders what might have been if the 27-year-old had not picked up a serious ankle injury at the start of the season and only returned to full fitness 10 days ago. He was outstanding at Schalke, alongside the “BBC”, gifted sub Benjamin Henrichs (19) and centre-back Jonathan Tah.

Leverkusen’s journey to where they were last year and should be in this one – just behind Bayern and Dortmund – might have been much rockier than anticipated, thanks to Schmidt’s touchline misdemeanour and tactical intransigence. But the fact that they are getting there again while so many blue-chip clubs are slugging it out at the wrong end of the table, again, should still be considered a minor triumph of smart transfer policy and coaching.

Talking points

• Borussia Dortmund’s captain Mats Hummels is losing “30 minutes of sleep every night” as he ponders a move away from the Westfalenstadion. The CEO Hans-Joachim Watzke has vowed to fight as hard as never before to keep the German centre-back in a yellow kit next season, but Bayern are reportedly ready to re-sign the player they lost for only €5m in 2008, for six times that figure. There were times, not that long ago, when Dortmund would have been quite happy to do that deal but Hummels’ form this season and his importance in the dressing room is such that his departure would be a serious blow. Whether the centre-back is merely letting down Dortmund gently or preparing the ground for a heroic contract extension beyond 2017 remains to be seen.

• Definitely out, before the season has even finished, is Nicklas Bendtner at Wolfsburg. The Dane probably lost more than 30 minutes of sleep per night during his less-than-happy stay at the Volkswagen-Stadion – he slept through training a couple of times – and the Lower Saxons have now decided that they no longer wanted to be a House of Lord. “Both Nicklas and ourselves had high hopes of his engagement at VfL Wolfsburg, but after two years we have had to realise that the expectations were neither fulfilled for him, nor for us, and a continued cooperation made no sense for either side,” read a club statement.

• Definitely out, Part II: Hannover 96. The Lower Saxons were relegated for the first time since 1989 after drawing 2-2 with Ingolstadt on Saturday. The Bundesliga has lost another big(ish) name but sympathy for their plight will be in short supply: club president Martin Kind has expended so much time fighting skirmishes with the supporters and pushing for a relaxation of ownership rules that he neglected the simple things: hiring a decent sporting director and manager, for example.

Results: Hamburg 2-1 Bremen, Köln 4-1 Darmstadt, Ingolstadt 2-2 Hannover, Stuttgart 0-3 Dortmund, Wolfsburg 0-2 Augsburg, Hertha 0-2 Bayern, Schalke 2-3 Leverkusen, Gladbach 3-1 Hoffenheim, Frankfurt 2-1 Mainz.