The flight from Lisbon to Dusseldorf was a full three hours long.
A 2-2 draw away from home wasn't a bad result.
But the match still had a significant impact on Dortmund.
Wang Shuo felt that this was the match, so far this season, that had truly shown Dortmund the intensity of European competition.
Dortmund had exposed quite a few problems in this game.
The team's defense wasn't a major issue.
The essence of Klopp's tactics was for the team to win the ball back in the shortest time possible after losing possession.
This required an immense amount of energy, which was why Dortmund's players expended so much of it.
But for now, the team was getting better and better at it.
The real problem still lay with the offense.
Götze and Reus were still too young, too green.
And then there was Shahin.
The midfielder was certainly very good, but on the European stage, especially in high-intensity matches, he still wasn't quite strong enough.
It was just as the pundits were saying.
