For Hansi Flick, the evening should have been about a developing side finding rhythm. Barcelona scored either side of half-time, looked lively in patches and gave supporters another glimpse of a reshaped squad.
But friendlies often reveal mood as much as form, and the reaction to De Jong exposed a tension that has been simmering for some time.
The midfielder remains sidelined with a knee problem, and reports suggest he is expected to miss the start of the new campaign, with a return anticipated around November. That absence leaves Flick without one of his most experienced midfield options.
What matters now is that De Jong has tried to shut down the wider chatter. On the suggestion he refused to play in a major game last season, De Jong said: “That is not true. It is simply not correct.” On talk of friction with his manager, he insisted their relationship was “actually very good”.
That split reaction inside the stadium - some boos, some applause - tells its own story. De Jong is still a major figure at Barcelona, but he also seems to sit at the crossroads of expectation, frustration and uncertainty.
The next test will come when the competitive season starts. Barcelona may move on quickly if results follow, but until De Jong is fit again, his name is likely to remain one of the club’s biggest talking points.