Union Berlin 0-3 Borussia Dortmund
(Reus 18' 25', Guerreiro 71')
Stadion an der Alten Försterei

It's a well-known fact that a certain M-word is not appreciated at Borussia Dortmund.

Players, coaches and officials alike bristle at the very mention of word "Mentalität" or the suggestion that the team is constantly held back by some inherent psychological weakness.

And indeed, a weak "mentality" is a rather bizarre character failing to throw at a group of elite athletes who have managed to reach the top level of professional football.

Perhaps another M-word is more apt to describe Borussia Dortmund these days: mystery.

How else can you describe the difference between last Sunday's 5-2 drubbing at home to Bayer Leverkusen and this weekend's commanding 3-0 win away at Union Berlin?

'More stability' in midfield

There are some immediate tactical explanations. The return of Axel Witsel gave Dortmund more bite in midfield and afforded Jude Bellingham, Julian Brandt, Raphael Guerreiro and Marco Reus greater license to go forward.

"With two defensive midfielders, we had more stability after losing the ball," explained Mats Hummels, whose own return brought experience to a leaky defense which will be further boosted by Niklas Süle next season.

"I think that Marco (Reus)'s best qualities are in and around the box, and his shooting. The further forward he is, the better for us."

Two clinical first-half finishes from the Dortmund captain underlined that point, before determined work from Bellingham set up Guerreiro for the third goal in the second half.

Dortmund prepared to fight

But there were also other less tangible qualities to Dortmund's performance in Köpenick, where they stood their ground in the face of Union Berlin's typically aggressive midfield pressing and, in doing so, secured a deserved first ever win in East Berlin.

Was that – whisper it – the right mentality?

"We wanted to take on the fight today, which we haven't done here in recent years," said Reus.

"We were extremely professional, especially in the first half. That's what I expect from us. There was a lot of frustration after last week and we wanted to let it out, and we showed the right reaction."

Rangers in the Europa League

The same qualities will be required on Thursday night when Dortmund embark on their Europa League campaign at home to Rangers.

Mentality shouldn't be an issue. But this Dortmund team still remains a mystery.

Edited by: Ruairí Casey