Gerard Pique was clearly trying to stir things up in the tunnel after half-time.
As the sides returned from the dressing rooms after the break in Sunday's El Clasico, Pique approached Real Madrid defender Nacho.
Pique leaned over and, behind his hand, said something that appeared to infuriate Nacho.
Cameras couldn't pick up what the Barcelona centre-half said but Spanish outlet
Marca have translated what Nacho's response was.
"How can you complain, if they have already dismissed us 17 times already?" Nacho said in response to Pique, who was presumably grumbling about the red card which had been shown to Sergi Roberto on the stroke of half-time.
https://twitter.com/casadelfutbol/status/993221799176531969
Nacho was dismissing any suggestions of bias by claiming that Real had suffered more from red cards in recent years.
Saturday's game was an ill-tempered occasion in which eight yellow cards were also dished out.
Real defender Sergio Ramos, who played peacemaker during the altercation between Nacho and Pique, revealed that Barcelona talisman Lionel Messi tried to influence the match officials at the break.
"Messi put pressure on the referee in the tunnel at half-time," Ramos said in his post-match interview.
"I don't know if there were cameras, and I don't know if he would have made other decisions in the second half.
"However, it's important to leave these things on the pitch, you have to show respect."
