It had to be him. Waldemar Anton can’t have relished changing ends at half-time on Saturday. The performance of Borussia Dortmund’s big summer purchase had already captured the defender’s time so far in Nord-Rhine Westphalia in microcosm, as his blind backpass led to former teammate Deniz Undav going one-on-one with Gregor Kobel. Only a swift intervention from Emre Can prevented Anton’s error from leading to a Stuttgart goal.

When BVB moved from defending the Südtribune in the second period, it became even more uncomfortable for Anton. He was that bit physically closer to the away Stuttgart fans in the north-eastern corner of Signal Iduna Park and their jeers and boos became more audible. They had been furious when the Uzbek-born centre-back had left, not so long after Anton had extended his contract and spoken of his pride at becoming Stuttgart’s captain. If the move north had come with a hefty bump in pay and status for Anton, it has so far been far from a resounding success and in a game in which Stuttgart created little of substance, his next inadvertent intervention felt almost inevitable.

Related: European football: Barça close in on leaders after thrashing Sevilla

Five minutes into the second half Chris Führich crossed from the right and Anton slid to block, but the ball skewed from his challenge and inside Kobel’s near post, giving Stuttgart the lead. In that corner the travelling fans, on their way to enjoying their fifth straight win over Dortmund, revelled in their former captain’s discomfort.

There was worse to come for Anton, and for Dortmund. Ten minutes later the ball dropped in Dortmund’s penalty area at the feet at Serhou Guirassy, who like Anton made a lucrative move from last season’s Bundesliga runners-up to BVB. The striker had time to clear but took too long, was dispossessed and eventually Jamie Leweling found a pass for Jeff Chabot of all people – Anton’s replacement – to rattle in his first Stuttgart goal, which turned out to be the winner after Julian Brandt later pulled one back for the hosts. Months after Stuttgart were faced with the prospect of rebuilding without the two totems of their epochal season, Anton’s and Guirassy’s new club is tasked with a far more daunting reconstruction project.

The symbolism of it was important because although this was another damaging result, it wasn’t really about this, but about everything that led Dortmund to this point. This was the first game in charge for Niko Kovac, Nuri Sahin’s replacement, who became the first BVB head coach not to win on his debut since Thomas Doll in March 2007. Kovac, like Doll, might privately wonder what he was reasonably expected to do on such short notice. His first steps in charge of his fourth Bundesliga club were broadly positive despite the result, with BVB looking more engaged, intense and compact. “We controlled the game,” Kovac told Sky. “We just had to score. We shouldn’t have left the pitch as losers.” Yet as so often in the recent past, a lack of poise at both ends of the field cost Dortmund.

It is tempting to suggest that no clarity in the boardroom means precious little on the pitch. Kovac should have been the headline here but he was overshadowed not only by the misadventures of Anton and Guirassy but by the midweek exit of Sven Mislintat, the transfer guru whose presence has stoked discord almost from the moment he returned to the club for a second spell. The internal relief at Mislintat’s departure was made clear with BVB’s official statement last Thursday, 29 words of text that you would struggle to match for curtness.

Those on-edge vibes will not end with Mislintat’s exit, as the ostentatious billboard advertising for controversial club sponsor Rheinmetall underlined. Six points behind Stuttgart with 13 games to go should not be fatal in itself to hopes of returning to the Champions League. But there is nothing in the ether to suggest BVB are capable of summoning the consistency to hunt their rivals down (and not just Stuttgart – Sunday’s win for RB Leipzig against St Pauli putting them into fourth, a further point ahead).

Bayern Munich 3-0 Werder Bremen

Borussia Dortmund 1-2 Stuttgart

Mainz 0-0 Augsburg

Freiburg 1-0 Heidenheim

Hoffenheim 0-4 Union Berlin

Wolfsburg 0-0 Bayer Leverkusen

Borussia Mönchengladbach 1-1 Eintracht Frankfurt

Holstein Kiel 2-2 Bochum

RB Leipzig 2-0 St Pauli

Stuttgart are a useful yardstick, though. This is also a huge club with a storied past that lived in administrative chaos for years, and is showing that reorganisation is a clear route to improved performance, whatever the budget. They get past the departure of key players because the approach, upstairs and downstairs (with the excellent Sebastian Hoeness on the bench) is consistent. Dortmund’s stars, be it Guirassy with his goals this season or Erling Haaland and Jude Bellingham in the recent past, merely paper over the cracks.

If Kovac can lift the mood and make Dortmund competitive again, in the Bundesliga and with a Champions League playoff against Sporting on the horizon, it would be quite the achievement. It will be hard, with the schedule against the new coach as much as the situation. “Because we play every three or four days, we have a lot of video study ahead of us,” Kovac underlined. He is a coach who is good at getting his players to focus on the basics, which is all that can be done now to try and arrest a season which has spiralled out of control.

Talking points

• The dynamics of next week’s huge face-off between Bayer Leverkusen and Bayern Munich changed with this weekend’s results; Bayern winning 3-0 against Werder Bremen on Friday night with a pair of Harry Kane penalties and Leverkusen only managing a goalless draw at Wolfsburg means that the gap at the top is now eight points. Leverkusen couldn’t really afford to lose before and now, perhaps, they have a near obligation to win.
  

• The schedule is the X-factor here, with Bayern facing a Champions League trip to Celtic on Wednesday. Leverkusen’s own midweek exertions were clear in an uncharacteristically flat performance at Wolfsburg after Wednesday’s effort in the Pokal quarter-final comeback against second-tier rivals Köln, with a trademark 96th-minute Patrik Schick leveller and an extra-time winner by Victor Boniface needed to seal the deal. A record-equalling run of 27 unbeaten away games was scant consolation after Florian Wirtz missed a sitter to score the winner in stoppage time (which, in fairness, he brilliantly created for himself). Xabi Alonso defended his decision to use Wirtz only as a substitute after his 120 minutes against Köln. “I take full responsibility,” said the Spaniard.
  

• Hoffenheim must be thrilled with BVB’s struggles as they overshadow their own status as the league’s crisis club. Head coach Christian Ilzer has seen his team win one out of 10 Bundesliga games, also exiting the Pokal and Europe. The league is the main worry, though, now. They are just four points above the relegation playoff spot, and morale is on the floor. “If we play the way we did today,” warned Marius Bülter after the 4-0 home hammering by Union Berlin, “we won’t win another game this season.”