Efficiency trumping brilliance for Real and Barca
An opening day draw has been followed by three consecutive victories with only one goal conceded, but the Bernabeu expect more, and grumbled and whistled at their side during the laboured 3-0 win over Espanyol midweek.
They head off to play promoted Levante on Saturday and then face another trip next Tuesday to take on Auxerre in the Champions League.
"The fans want to see football played at pace but they have to remember that we are having to play a lot of games in quick succession," Germany midfielder Sami Khedira told reporters.
"There is an accumulation of fatigue and stress so the idea is that we conserve our energies."
Mourinho has had little time to work with his full squad because of the recent rush of fixtures, but defensive solidity has made up for a lack of fluidity in attack so far.
Saturday's hosts Levante should not ask too many questions of Real. They won their first points of the season beating Almeria 1-0 away on Wednesday, but have already leaked 10 goals.
Mourinho has a one-point lead over champions Barcelona, who have also been struggling to produce their best football so far this season.
Barca were camped in their own area defending a 1-0 lead at home to Sporting Gijon when the referee blew for time on Wednesday, and Pep Guardiola sounded similar to Mourinho as he sought to explain a below-par performance.
"It was very difficult to find any space. We may not have been brilliant but the team were very stable," he told reporters.
Against Atletico Madrid last weekend and Sporting, Barca have failed to convert chances which could have killed off the games much earlier, making life more uncomfortable for themselves.
The last thing they need ahead of a gruelling trip to play Rubin Kazan in the Champions League next week is a visit to Athletic Bilbao's San Mames.
The Basque side are always a tough proposition in front of their own fans, and Barca will be without the injured Lionel Messi once again.
Valencia dropped their first points of the season at home to Atletico Madrid on Wednesday, when visiting goalkeeper David De Gea ensured they were held to a 1-1 draw. They return to action at Sporting on Saturday.
Atletico are at home to basement side Real Zaragoza on Sunday when Sevilla visit promoted Hercules.