Marco Reus said Borussia Dortmund are lacking both luck and confidence following a Champions League loss at Barcelona.

Dortmund slipped to a 3-1 defeat at Camp Nou on Wednesday with Lionel Messi providing two assists, scoring and hitting the crossbar in a superb showing on his 700th appearance for Barca.

Although Jadon Sancho inspired Dortmund from the bench after his half-time arrival, scoring once and forcing Marc-Andre ter Stegen to turn a drive onto the crossbar, Dortmund are without a win in three games in all competitions.

They have conceded 10 times during that run to pile the pressure on under-fire coach Lucien Favre with Reus accepting Dortmund, who now need help from elsewhere to qualify for the last 16, are struggling.

"We knew what we were up against," Reus said.

"We moved the ball well enough, but had problems with penetration in the final third.

"If we lose the ball there, we have to be braver when pressing and do so with more energy.

"Currently things are not going in the right direction for us. We are lacking some good luck as well. 

"It is always our goal to win a game, but I have to admit we are not full of confidence."

Dortmund are at home to Slavia Prague on matchday six next month but will not qualify if Inter beat Barca at San Siro.