Real coach Jose Mourinho sent the Brazilian attacking star off in the 87th minute of Tuesday night's game against the Nerazzurri. Alvaro Carreras was supposed to replace him, but that did not happen straight away.
With Vinicius, in referee Michael Oliver's view, taking too long to leave the pitch, clearly trying to run down the clock with Los Blancos 2-1 up, Carreras was immediately refused permission to come on.
Madrid therefore had to play with 10 men for a spell and almost paid for it. Inter tried to use their numerical advantage and, after an attack down the left, Henrikh Mkhitaryan got his shot away. Real goalkeeper Thibaut Courtois only just managed to deal with the former Dortmund player's effort.
Only when Los Blancos cleared for a corner and brought about a stoppage in play was Carreras allowed to enter the pitch. By then, more than a minute had already passed since Vini Junior's substitution, during which the 23-year-old had been standing on the touchline.
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Which new rule was applied to Vinicius Junior?
Referees have had the option since the World Cup to delay substitutions if the player being replaced takes unnecessarily too much time to make his way back to the bench.
Because Vini Jr. took significantly longer than the maximum permitted 10 seconds to walk to the touchline, he applauded towards the stand as he left the pitch, where whistles could be heard against him at times, referee Oliver opted to apply the new rule strictly.
The incident had no bearing on the final result. After goals from Kylian Mbappe and Federico Valverde, Madrid edged their Champions League opener 2-1. Inter's only reply came through Carlos Augusto.