Sergio Ramos criticised referee Ricardo de Burgos Bengoetxea for sending off Cristiano Ronaldo as Real Madrid secured a 3-1 win over Barcelona in the first leg of the Supercopa de Espana at the Nou Camp.
Substitute Ronaldo restored Real's lead with a brilliant effort from range 10 minutes from time, but was sent off two minutes later after picking up a second yellow card for diving after going down under pressure from Samuel Umtiti.
To compound matters, the Portugal forward - linked with a move away from the Bernabeu this summer - then pushed De Burgos Bengoetxea after being shown a red card.
Gerard Pique's own goal had put Real ahead after a low-key first half, but in a frantic finish Lionel Messi equalised from the spot before Ronaldo struck, with Marco Asensio grabbing a last-minute third for the 10 men.
Real skipper Ramos said of the second booking, in quotes reported by Marca: "I was far away, but I think it was a piece of play in which (Ronaldo) lost his balance, rather than feigning anything.
"It could be appealed. Sending off a key player with 10 minutes remaining of a Clasico in which we've given our all is something which needs to be evaluated and thought about."
Barcelona's penalty was awarded after Luis Suarez was brought down by goalkeeper Keylor Navas, and Ramos also took issue with that decision.
"In no moment was it a penalty," the Los Blancos defender added.
"I will need to watch it and evaluate it because I don't think the referee would blow for an action in which there was nothing there, knowing that he could be mistaken.
"My feeling was that it wasn't (a penalty)."
Barcelona boss Ernesto Valverde insisted the tie was not over ahead of Wednesday's second leg at the Bernabeu.
He told Barca's website: "We have to look ahead as there is still the second leg to come. Even though they will be favourites, the game is still there to be played.
"It was a game in which we had some good moments and in which we were caught out on the counter by two great goals.
"We had chances in their area and I think we were closer to scoring than they were but when you do that you can switch off against Real Madrid.
"You never like losing, even less so against Madrid, but aside from the blow of the defeat there are things that we can take from the game."