Barcelona coach Hansi Flick said on Saturday he is unsure if teenage winger Lamine Yamal will be fit to start the La Liga leaders' visit to face Real Sociedad on Sunday.

The coach also said he thought playmaker Dani Olmo would be ready despite feeling unwell overnight, while defender Pau Cubarsi can play despite suffering a cut on his face during the team's Champions League win over Red Star Belgrade on Wednesday.

"Pau, I think (he will be fit), he trained with us for the whole training session," Flick told reporters.

"Lamine, he was (working) inside and did specific strength training. He's had a lot of matches in the last weeks so we took care of him... we'll see what the situation is tomorrow.

"With Dani he felt a little bit uncomfortable at night and this morning is doing better, so with him just treatments and medical things, I think he's ready for tomorrow."

Barcelona held a nine point lead on second-place Real Madrid heading into the weekend.

Flick also emphasised the importance of punctuality for his players.

Spanish media reported French defender Jules Kounde was left out of the starting line-up to face Alaves in October after arriving late for a team meeting.

"It's a rule. I don't speak about what happened in the past, it's just about respect for the team," said Flick.

"If you are five minutes too late, the others have to wait, this is not respect, this is not my understanding of being respectful."