Mats Hummels urged Borussia Dortmund to improve defensively following the 2-2 Bundesliga draw with Stuttgart.
Jurgen Klopp's side were forced to come from two goals behind to earn a home point on a disappointing evening, as they dropped points for the third time in five league games this season.
Daniel Didavi's double looked set to earn Stuttgart, who announced the sacking of sporting director Fredi Bobic shortly before kick-off, an impressive win.
But with a second successive league loss appearing likely, Pierre-Emerick Aubameyang and Ciro Immobile rescued a share of the spoils - not that club captain Hummels, who was introduced as a late substitute following his recovery from injury, was satisfied.
He told Dortmund's official website: "We need more defensive stability. We have already conceded nine goals in five games.
"We have to defend better as a team. Only then can you successfully play football.
"If you concede two goals in each game, as has already happened four times this season, it's damn hard to win."