The Argentine readily admitted to Real Sociedad being better in every way, while Andres Iniesta is not too concerned about Barcelona's La Liga standing yet.
Lionel Messi's strike and leap to third in La Liga's all-time top scorers charts proved scant consolation as the Blaugrana were outdone by Antoine Griezmann and David Zurutuza, as well as an own goal by Alex Song.
And Martino, who was sent to the stands at halftime for calling La Real's assistant coach an idiot in Argentine, admitted his men were totally inferior to their hosts.
"I didn't prepare us for the game well enough, Real were the better team. Now we have to get up, we have a week to prepare the next game," the 51-year-old told reporters. "It was probably a mistake not to make changes when the score was at 1-1. Introducing Xavi wouldn't have made any sense, as [Cesc] Fabregas and Alexis [Sanchez] were already present.
"I don't have anything to say about the decision to send me off. The referee made that decision and that's that."
Defeat sees Real Madrid go three points clear at the top of the table, but Andres Iniesta refused to throw in the towel yet despite acknowledging the setback.
"The league is tight, so this defeat is a step back," the midfielder stated. "It isn't a good feeling, but the league isn't over yet."
The Catalans will seek to get back on their feet next Sunday when they host Almeria at Camp Nou.