Barcelona fielded a weakened side in their Champions League game at home to BATE Borisov last night. They could afford to, as they had already qualified as group winners, but they also really needed to do so.
The Catalans face Real Madrid away on Saturday night in the Bernabeu. From Madrid they fly to Japan for the World Club Championships.
The Primera Liga is only 15 games into a 38-game season, but Barcelona are three points behind their great rivals and have played a game more.
The gap, effectively six points, could increase to nine on Saturday if Real win. Such is the form and strength of Jose Mourinho's side, they do not look like they would drop another nine points all season.
In Amsterdam tonight, Real will similarly rest their top players because, like Barca, they have already won their Champions League group.
Like Barca, they are aiming to win the domestic and European title. Both sides are good enough and more than justify their status as first and second favourites in both competitions, but something has to give.
Real's training sessions on Monday focused not on the immediate game in Amsterdam, but the game on Saturday against the Catalans. The media have started their customary conjecture and nonsense, but this game does not need the hype.
A victory for either club will set the template for the season to follow, just like the first clasico last season where Barca won 5-0. Then, the "morale blow" which so many players mentioned was as big as the loss of three points.
Lionel Messi is set to win his third consecutive Ballon d'Or - and match Uefa president Michel Platini's achievements in the 1980s while the Frenchman was with Juventus.
Eight Barca players and their coach Pep Guardiola are among the 55 nominations for Uefa Team of the Year - individual awards given to players who have been part of a winning collective.
Barca feature so prominently because they are so dominant, but if they slip behind Real in Spain then it will be the whites who receive the nominations and Ronaldo who wins the individual awards which he covets so much.