Ronaldo has scored just twice in four games played so far this season, including a fine free kick late in the 2-1 UCL opening game win at home to Sporting Lisbon, after joining preseason training late due to a knee injury suffered during the Euro 2016 final.

When substituted early in Sunday's 2-2 draw at Las Palmas, the 31-year-old reacted angrily, with TV pictures appearing to show him insulting his boss and using foul language while watching the rest of the game.

The Blancos coach told his pregame news conference ahead of the Dortmund clash that it was normal for a player to be angry at being taken off in a game, but both he and Ronaldo had already moved on and were concentrating on winning the next one.

"Everything is normal," Zidane said. "It is not just Cristiano -- all players can be angry when they leave the pitch. We're already thinking about tomorrow's game. I took the decision for the good of the player.

"Nothing has changed. All this talk [about the incident], more than about tomorrow's game, well we must live with that. We are relaxed. I'm not stupid, and he is intelligent. We are all here for the same thing."
Cristiano Ronaldo was subbed off in the second half of Real Madrid's 2-2 draw against Las Palmas.

Madrid remain unbeaten this season but have drawn their last two games against Villarreal and Las Palmas, allowing Barcelona and Atletico Madrid to draw closer at the top of the La Liga table.

"This can happen, and maybe will happen again in the season," Zidane said. "But the team is good. Nobody likes dropping four points in two games, but football is like that. Sometimes it is good to get a jolt -- and then to keep going with our work."

Madrid have lost on their last three visits to the Westfalenstadion -- when Zidane was at the Bernabeu club in a back up role to previous coaches Carlo Ancelotti and Jose Mourinho.

"Each game is different, it will be difficult, as all games are," he said. "[Dortmund] have young players, have made changes, but the philosophy of this club has not changed. They like to play football. We are the same -- we will play football too."

Centre-back Pepe returns from a knock and is available to start, while fit again Keylor Navas could take over from Kiko Casilla in goal, with Fabio Coentrao possibly playing at left-back given first choice Marcelo is injured.

"I speak with the keepers and they know who will play, but I will not tell you now," Zidane said. "The important thing is for both to be ready. Coentrao is fit again and with us now. Both he and Keylor are ready to play 90 minutes."

Zidane admitted that a current injury to holding midfielder Casemiro was a blow, however he was comfortable rejigging his centre-field to cover.

"Casemiro is an important player, as they all are," he said. "At first [youngster] Marcos Llorente was with us, a player who could cover. Then we took decision with the club, together, [for him to go on loan to Alaves]. Now we must do things differently, and we can do that, we have very good players to do that.

"The same position, maybe not, but we can do a different thing with a different player. We can also play a 4-4-2. It depends on what we want to do on the pitch.

"For me the system is not so important. It is more important that player is happy where he is playing."