Joao Cancelo's challenge on Yan Diomande sparked plenty of controversy in the 60th minute of the Clasico, pitting the Barcelona man against his Real Madrid opponent.
According to the newspaper AS, the referee waved play on after Cancelo stamped on Diomande, who felt pain in his leg muscle as a result.
Iturralde Gonzalez, the refereeing analyst for AS and Cadena SER radio, reckons the Barcelona defender should have been booked for the incident.
He said: "This is not a case that calls for the intervention of VAR technology. It is a clear yellow card, and the player should be cautioned."
He stressed: "But it is not a clear stamping action involving the use of excessive force on the opponent's leg. Yes, it is a yellow card."
Archivo VAR, the website specialising in refereeing incidents, took a similar line: "Does Cancelo's challenge on Diomande deserve a straight red card? No."
Its verdict went on: "Cancelo made the challenge with the sole of his foot, without applying excessive pressure, and it ended in a contact that led to a scrape on the area of his opponent's calf muscle."