By and large, Borussia Dortmund have put together a decent start to the season.
Many predicted the Black and Yellows would stumble out of the gates a bit following a massive squad overhaul during the summer transfer window, and those auguries have proved correct.
Still, they are not far off their target for the season in the Bundesliga after 10 rounds of matches, sitting fifth in the table, two points behind TSG Hoffenheim in the third spot that qualifies directly to the UEFA Champions League.
In Europe's elite club competition, Dortmund have already advanced to the last 16 with two matchdays to go and are at least guaranteed to have what is essentially a play-off for the group win against Real Madrid at Santiago Bernabeu in early December. If they beat Legia Warsaw at home and Los Blancos drop points at Sporting CP, Dortmund could even win the group on the next matchday.
In the DFB-Pokal, a makeshift BVB side needed penalties to advance against Union Berlin in the second round, but making it through is the only thing that matters in the cup.
That said, it is obvious the Ruhr side is not playing at the same level on display last season. Dortmund clearly miss three key players who left for greener pastures in the summer.
Even though they have done fairly well in replacing those departures on the transfer market, one can safely assume the Black and Yellows would look better had Mats Hummels, Ilkay Gundogan or Henrikh Mkhitaryan stayed at Westfalenstadion.
Given Bayern Munich look surprisingly beatable in the Bundesliga—they have dropped points against Cologne, Eintracht Frankfurt and Hoffenheim—chances are BVB could even have challenged for the title with those three.
But whom do Dortmund miss the most? Here, Bleacher Report takes a closer look.
The Case for Mats Hummels
Before his transfer to boyhood club Bayern was announced in May, this writer argued that Mats Hummels' departure for Munich would be the biggest blow to Dortmund yet.
The 27-year-old was more than just a world-class centre-back for Dortmund. He was a leader on and off the pitch, a mouthpiece and face of the club, especially after Jurgen Klopp left and the less charismatic, more schoolmasterly Thomas Tuchel took over.
ESPN FC's Stefan Buczko summed it up pointedly. "By handing in his captain's armband of the German vice-champions, the leader of BVB's rebellion against Bayern's monopoly is waving the white flag," the Dortmund-based writer wrote. "Hummels is showing everyone in the league that resistance is futile and that he is prepared to ditch his BVB legacy for the likeliness of silverware."
Losing their captain and leader to their biggest domestic rivals was much worse than losing Gundogan and Mkhitaryan to Manchester City and Manchester United, respectively. It put Dortmund in their place as a distant No. 2 in German football.
One could argue, however, that his loss on the pitch was not quite as devastating.
For all of Hummels' class, the Germany international was struggling for form for longer stretches of games during the latter stages of his career in the Ruhr valley. He was downright bad for more than half a year following the 2014 FIFA World Cup, which contributed to the club's fall into the relegation zone during Klopp's final season.
Even in Tuchel's maiden campaign, Hummels only started playing to his capabilities after a few months of searching for form.
That does not mean, though, that he is not a world-class centre-back. First and foremost, he is one of the best ball-playing defenders on the planet, which has incredible value for a possession-orientated system such as Tuchel's.
Dortmund are struggling to play out from the defensive zone this season, even though both Matthias Ginter and Marc Bartra have shown they have the talent to pick up some of the slack in Hummels' absence.
Bartra, who came to the club for a bargain €8 million from FC Barcelona in the summer, looked especially promising early in the season—before he picked up a muscle injury—as this video from tactics blogger Tom Payne shows:
Dortmund do miss Hummels, and his transfer had a highly symbolic meaning in the context of the rivalry with Bayern, but the two other departures arguably hurt the club more on the pitch.
The Case for Henrikh Mkhitaryan
There can be little doubt Henrikh Mkhitaryan was Dortmund's best player last season. Beyond incredible scoring numbers—23 goals and 32 assists in 51 matches, per Transfermarkt—the Armenian embodied the change in philosophies between the reigns of Klopp and Tuchel.
"When Tuchel came, we started to play a different kind of football," he told B/R in an exclusive interview earlier this year. "We try to keep the ball more, we try to pass it more and play very offensive football."
Mkhitaryan was the perfect attacker for 43-year-old's system. A technically sound player with excellent speed, vision and tactical awareness, he regularly punished teams that allowed him too much space. Knifing inside from his usual starting position on either wing, Mkhitaryan made the half-spaces his hunting ground and went for the kill with surgical precision.
The 27-year-old and Tuchel seemed a match made in football heaven. The head coach's ability to get the best out of Mkhitaryan's struggling genius was one of the biggest reasons for Dortmund's strong campaign.
Then Manchester United came along, offered the Armenian a lot of money and the Black and Yellows a club-record transfer deal worth a Transfermarkt-reported €42 million (£36 million).
Mkhitaryan's struggles at Old Trafford are well-documented, and many Dortmund fans cannot hide a bit of schadenfreude. That extends to the club's chief executive Hans-Joachim Watzke, who categorically ruled out a future Mkhitaryan return in an interview with German sport magazine Kicker.
"Any intelligent player should consider in advance what kind of environment they are moving to," he said (h/t Stephan Uersfeld of ESPN FC). "When you are playing in surroundings where things are working for you, like in Dortmund, then it is quite strange to give that away again once things have finally started to work out for you after a long time settling in."
Mkhitaryan's more than disappointing start to life under Jose Mourinho notwithstanding, it is obvious that Dortmund miss their best player from last season. The Black and Yellows have only Pierre-Emerick Aubameyang as a consistent threat on goal—his 14 goals across competition are followed by three each for Gonzalo Castro, Raphael Guerreiro and Adrian Ramos.
The team's attacking play has looked laboured, predictable and even slow at times this season. The Mkhitaryan of 2015-16 would be just what the doctor ordered.
That said, Dortmund replaced the Armenian with two exciting youngsters in Emre Mor and Ousmane Dembele, as well as club-record, €30 million signing Andre Schurrle. Academy product Christian Pulisic has also received more playing time following Mkhitaryan's departure and injuries to Schurrle and Marco Reus.
The Black and Yellows are missing the Armenian and his quality on the pitch, but they have a number of exciting options to take his place.
The Case for Ilkay Gundogan
It is almost ironic that the player Dortmund should have been well-prepared to replace has so far proved to be irreplaceable. Ilkay Gundogan missed so many matches over his career at Westfalenstadion that the club had ample opportunity to prepare for life without the midfielder.
Even in his last season at the club, in which he returned to world-class form, Gundogan missed 13 matches during the second half of the campaign. Some would argue it cost the club silverware, as the Germany international missed all but eight minutes of the UEFA Europa League quarter-final meetings with Liverpool, as well as the cup final against Bayern.
If Mkhitaryan was the man to make things happen in the final third, Gundogan was the player who made Tuchel's system work.
One of the best conductors in European football, the 26-year-old was arguably the most important player on the pitch, responsible for the team's structure and organisation in possession. His statistics—three goals and seven assists, per Transfermarkt—did not show it, but Gundogan put his stamp on Dortmund's play more than anyone else.
It is by no means a coincidence that he is now tearing things up at Man City under Pep Guardiola, recently scoring a brace in the Champions League against Barca, as Dortmund fan David Schafer pointed out:
It makes the club's decision to not sign a like-for-like replacement all the more baffling. Dortmund acquired three wingers after Mkhitaryan's departure but not a single creative central midfielder.
Returnee Mario Gotze has taken on some of Gundogan's responsibilities but cannot be expected to have the same strategic influence. Sebastian Rode, who is more of a box-to-box midfielder than a playmaker anyway, has all the makings of a failed signing.
One could argue it would have been impossible for Dortmund to sign anyone close to Gundogan's world-class quality, but the fact they did not even get someone in who could grow into that role is hard to justify.
The club may get lucky if Guerreiro continues to develop in central midfield after playing most of his career for FC Lorient and Portugal at left-back, however. The 22-year-old has so far only started three matches in that position.
Still, it is only fitting that the team is often struggling to advance the ball into the final third with any kind of authority and purpose. There is a gaping hole where Gundogan used to dictate the tempo of every attacking move.
Dortmund clearly miss the midfield mastermind the most.