Luka Modric and Gareth Bale have been left of Real Madrid’s squad for their Champions League clash with Galatasaray. The duo also missed Saturday's La Liga defeat to Real Mallorca after picking up injuries on international duty.
Lucas Vazquez will also be missing in Istanbul as Madrid look to salvage their woeful start to the group stage.
The former European champions have just one point from their opening two games, following a disastrous 3-0 defeat by Paris Saint-Germain with a strained draw against Club Bruges.
"We know what we're playing for," Zidane said of Tuesday's trip.
"We need to play to win because there's no other option there. We need to focus on winning on Tuesday."
Last season was the first time since 2009-10 that Madrid failed to reach at least the semi-finals of the Champions League. What's more, they have lost three of their last five games in the competition, conceding three or more goals in each of those defeats.
“The problem is that every three days we have to prove that we're a good side,” he added.
“That's our problem and it's what we're not doing. I'm not going to tell you I'm concerned, but we need to have more continuity. We need to bring a bit more life to our play if we want to achieve big things this year."