The Spaniard was dismissed by referee Phil Dowd for bundling over Wickham inside the area as he raced through on goal on the stroke of half time at the Stadium of Light.
Fabio Borini stepped up to dispatch the resulting penalty and give the hosts a two-goal lead at the break in the process, and the Englishman has said that Dowd made the right call.
"Obviously I felt he pulled me down," he told Sky Sports News at full time.
"I felt I could have scored. If you go down, he's going to get sent off, but I felt I could score. But [Dowd] brought it back and I think he made the right decision."
The 21-year-old, who had fired the Black Cats ahead, rounded off the scoring in the closing stages of normal time after Emanuele Giaccherini added a third on 76 minutes.
Consequently, Gus Poyet's side moved out of the relegation zone in the Premier League table for the first time since February ahead of their three remaining fixtures.