Romanian referee Ovidiu Hategan has discussed how Jadon Sancho's dribbling style forces him to change his position.
The match official has explained all in a behind-the-scenes UEFA documentary focusing on referees.
It details some of the fiery conversations between themselves and players during European matches over the past two seasons.
Hategan was discussing his experience having taken charge of a game between Barcelona and Borussia Dortmund in which he gave a penalty after Nelson Semedo had fouled Sancho.
"Even now, I see in Dortmund they have a very good right winger from England [Sancho] and one against one with the defender, [he] always creates problems," he said on the UEFA documentary.
"When he has the ball, I always move a little bit on the right-side on my diagonal - so I broke my diagonal and I went on the right-side of the penalty area because I knew something could happen.
"I was in the perfect position, I've seen the stamp, clear foul and I whistle the penalty without any hesitation."
Marco Reus saw his spot kick saved by German compatriot Marc-Andre ter Stegen in a game that finished goalless.
That was the only major call Hategan had to make at Signal Iduna Park.
And after the contest he was quick to assess his performance with his team
"At the end of the match, you know as a referee if you have done a good match," he said.
"My team were very happy in the dressing room after the match.
"When I see the replay [in] the next days, I can hear the crowd signing because when I'm there on the pitch, I'm so focussed - I'm in my own world."
The four-part documentary follows the lives of 16 of UEFA's top referees - including Premier League officials Michael Oliver and Anthony Taylor.
