In itself, that was all the evidence required to suggest that the number to be illuminated on the substitution board had to be 10. Jose Mourinho has never been a manager who is afraid of removing players who have just made critical errors. And Rooney’s wastefulness was a critical error.

After a listless first hour, United had finally counter-attacked their hosts with something approaching the fluency and zest for which they were once renowned. Here was a real opportunity to conjure up an equaliser to Étienne Capoue’s fierce opening goal. Instead, Rooney undermined the revival with the kind of leaden-footed delivery that would draw the coach’s criticism, even in an under-10s game.

However, the bad news was that that one incident was by no means the low point of the United captain’s contribution. Almost wholly peripheral to the action, Rooney was about as mobile and effective here as an oak wardrobe. Yet, when the number came up to signal who Juan Mata was to replace, it was not 10, it was 25. To the bemusement of everyone in the stadium, Antonio Valencia was removed from the fray, not the man who had long been by-passed by the action.