Ernesto Valverde has confirmed Ousmane Dembele arrived late for Barcelona's Champions League win over Inter in midweek, but insists this will not influence his selection for El Clasico.
Barca saw off Inter 2-0, with Dembele an unused substitute despite Lionel Messi being sidelined with a broken arm.
Messi is ruled out once more for Real Madrid's visit to Camp Nou on Sunday, although the reshuffled front three of Luis Suarez, Rafinha and Philippe Coutinho are favourites to start after Valverde named a 19-man squad.
"I worry about what they can do as footballers, what they can do on the pitch. He was late the other day, yeah," the head coach told a pre-match news conference when asked about Dembele.
"When we were there for our pre-match team meeting he was there as he had to be.
"I don't think you should take things out of context and say that's why Dembele is not playing.
"He's young, we expect a lot from him. We focus on sporting matters alone."
France winger Dembele has five goals in 11 appearances for Barca this term, having been badly hindered by injury during his debut campaign at Camp Nou last time around.
Another big-money arrival under Valverde who has enjoyed more serene progress is Coutinho – the Brazil playmaker who is likely to be key to Barca's approach in Messi's absence.
"Coutinho's a great player," Valverde said. "He's got a great shot, he's a constant headache for defences because he's always creating.
"Of course, we want more from him and I'm sure he'll produce that."
Coutinho has been freed up to operate in the front three by the accomplished performances of his countryman Arthur in midfield.
"This is a big game for him. It's his first Clasico if he's fit enough to play," Valverde added, with regard to the stylish 22-year-old.
"He's been training well. He's fitted into our philosophy and the fans recognise that."