Zinedine Zidane said he was "very disappointed" after Real Madrid missed their chance to close the gap on La Liga leaders Barcelona as they could only gain a point from their visit to Athletic Bilbao on Saturday, 2 December.
Real created numerous opportunities at San Mames but could not find a way past Athletic goalkeeper Kepa Arrizabalaga, with the game ending in a goalless draw.
The result meant the Madrid club are still eight points adrift of Barcelona, who had drawn 2-2 with Celta Vigo earlier on Saturday.
Adding to Zidane's troubles, Sergio Ramos was sent off for two bookable offences at San Mames, while Dani Carvajal and Casemiro both picked up their fifth bookings of the season, meaning the trio will be suspended for the crucial clash against Sevilla next weekend.
A defeat to Sevilla would push Real out of the top four in La Liga and considerably raise the heat on Zidane.
The Frenchman insisted that his team had deserved to get all three points against Athletic and said he was sure that Barcelona would slip up again in the coming weeks.
"I go away from here feeling very disappointed, because after the good performance we put in, we deserved more from the game," Zidane told Real's official website.
"We played very well and had our chances, but the ball just didn't want to go in. It would have been great to claw some points back. We haven't managed to do so, but I'm sure that we'll get another chance to reduce the gap on the leading pack."
Meanwhile, Ramos broke the La Liga record for the most career red cards as he was sent off for the 19th time for elbowing Athletic forward Aritz Aduriz towards the closing stages of the match.
"Ramos is not happy as he thinks he didn't make contract, that it was not a yellow," Zidane was quoted as saying by ESPN.