Dortmund matched their worst Bundesliga defeat against Stuttgart on Saturday, with conceding 4 goals in the second half at Signal Iduna Park.
third game in a row without a victory, and currently fifth in the table, the Swiss manager,
, might be in danger of losing his job.
openly questioned his boss’ tactics.
"We always try to play small and small through narrow spaces and have a huge ball-loss rate,"
Hummels told Sky Germany.
"If it works, it looks like nice football. But it rarely does. That requires too much skill."
"A lot went wrong today,"
the 31-year-old continued
. "We didn't play a good first half either, but we went into the break happy to be level at 1-1."
The German defender believes his side’s extreme carelessness in possession cost them the match, as they conceded three goals in 11 minutes.
"2-1, we gave the ball away. 3-1, we gave the ball away. 4-1, we gave the ball away, we kept giving the ball away."
Former Germany international also praised the opponents:
“They did an excellent job, like they have been the whole season,"
. "They had a good plan, were aggressive and determined. And we weren't."
Dortmund will face
in an away Bundesliga match on Tuesday.