Ilkay Gundogan has admitted that Borussia Dortmund still need to improve defensively after claiming a third successive Bundesliga victory for the first time this season.
Despite dominating for long spells, Dortmund were given a scare in Friday evening's 3-2 triumph over Stuttgart and Gundogan claims that Jurgen Klopp's side must do a better job of killing off teams.
"We've collected nine points from the last three games, which is the maximum on offer. However, we've got to be somewhat self critical today despite the win," the German midfielder told reporters.
"We're getting ourselves in front in games, but haven't necessarily been able to keep countering the way we like to and then we end up conceding sloppy goals, like we did tonight from a late corner, which we should never allow to happen.
"Mental blocks can be a part of football sometimes, but the last three games have allowed us to break through that."
Dortmund return to action against Juventus in the first leg of their Champions League last-16 tie on Tuesday evening.
