Manchester City midfielder Yaya Toure admits they can't afford to slip up against Champions League opponents Borussia Dortmund.

Toure admits tomorrow's clash with Borussia Dortmund at the Etihad is already a must-win game for City because they lost their last game at Real Madrid.

"Of course we need to improve because when you play against tough teams like Madrid and Barcelona, we need to improve in difficult situations," said Toure.

"I think we made some mistakes in Madrid and the most important thing is to try not to repeat them.

"The Champions League is the toughest competition in Europe.

"We have got tough, tough teams in our group and the most important thing for us is to try and do our jobs.

"We know it will be difficult, but we will do everything we can to get through."