Just 26 minutes into the match, Subotic "assisted" Hummels, who put the ball into Dortmund's own net.
For a long time after that, Dortmund struggled to break the deadlock.
So, as the team's head coach, what was the right move?
"Just wait."
In the away team's dugout at the Black Forest Stadium, Klopp remained completely unruffled, confidently telling his assistant.
This scene unfolded during the 13th round of the Bundesliga, in Dortmund's away match against Freiburg.
In the 61st minute, Dortmund finally made their first substitution.
But Wang Shuo, the player the TV commentator had been calling for, remained on the bench.
Kuba came on for Grosskreutz.
"Dortmund is still struggling to break through on offense. Klopp should be bringing on Wang Shuo to bolster the attack, not making adjustments on the right flank."
"What on earth is he doing?"
"Is he giving up on this league match for the crucial Champions League game next Wednesday?"
