Clement Lenglet describes it as the fixture that "freezes time" and believes this week's Clasico double-header could still define the seasons of both his own Barcelona, and Real Madrid.
The two clubs will meet twice in four days at the Santiago Bernabeu, on Wednesday in the second leg of their Copa del Rey semifinal and then on Saturday, in a battle of first against third in La Liga.
Even victory is unlikely to project Madrid back into the title race but for Santiago Solari's side, momentum is at stake, their steady, if not unwavering, resurgence poised for a potential double boost ahead of the campaign's decisive months.
Barcelona's priority may be the Champions League and their hold on La Liga too tight to shake off but it says something for the magnitude of the Clasico that Lenglet still feels its significance.
"This month is pivotal," he says, in an exclusive interview with AFP.
"There is the Champions League and these two games against Real, when we can qualify for a cup final and then gain or lose points on them in the league.
"We have to manage them properly. It could be pivotal for the rest of the season."