Barca won 1-0 thanks to Robert Lewandowski's penalty, though the Pole was visibly unhappy when substituted. Kounde, meamwhile, was benched after arriving late for a team meeting, as Flick confirmed afterwards.
Match:
"I think we saw today what I said yesterday: Rayo plays very well. It was a tough game for the players. We are very happy with the three points, it was very difficult to win.
"It was a difficult win against a great rival. It was a very difficult job for the players and we are very happy. It is not good to look at the table too much, there is still a long way to go. But I am happy for the players. Our motto is to fight until the end. We take it game by game.
"I think it was a great success for us. Achieving that first place is positive. Now we are back and happy."
Koundé situation:
"It's part of football, these things happen. I think it's match day and for me before the match we all know what we have to do. Maybe there are two or three meetings with the players and it's very important that they attend the meetings. It's not that difficult to show up and comply. It's about respect. I have to talk to him. He arrived late, but it's a rule that must be made clear. That's what happened today."
Lewandowski's substitution:
"It's my decision. He wants to play and score. I make decisions thinking about the team, not the players. He has my support, but I'm the one who changes the players and he has to accept that."
Pedri:
"Extraordinary physical work is being done. Deco also did a great job when planning which experts and professionals should be there. And this is seen in the case of Pedri and with others. Pedri plays fantastically. He is a great player."
Rayo:
"They're doing very well. They've done an extraordinary job. He's (Inigo Perez) doing great. It's one of the best teams that has ever played here."
Lamine Yamal:
"The best thing is that he tries, and he is doing it. One day things happen and the moment will come when he scores a lot of goals. He has to work hard and show it in the game. He does it very well. He looks for opportunities. He finishes the actions he takes, he has not had the luck he needs, but he will get there."