Salvador Sostres explained Thursday in an apology published by Spanish newspaper ABC that he was trying to "praise the beauty of Ansu's movements" and that he was "deeply sorry for any misunderstanding," according to a translation by BBC Sport.
Fati, 17, scored and provided an assist in Barcelona's 5-1 victory over Ferencvaros in the Champions League group stage Tuesday. The goal made him the first player to score twice in the Champions League before turning 18.
But Sostres drew attention away from the impressive performance when he wrote in his match report that Fati was like a "Black street vendor ... (who) you suddenly see running" as soon as the police arrive, according to BBC Sport.
Fati's teammate Antoine Griezmann defended the winger on Twitter after Sostres' report came to light.
"Ansu is an exceptional boy who deserves respect like any human being," Griezmann wrote in Spanish, as translated by BBC Sport. "No to racism and no to rudeness."