Mike Maignan tired of the noise from Udinese supporters and left the pitch in Saturday's Serie A match.
Only after the announcer called on the crowd to stop using racist slurs did the match resume after a short break.
The president of the International Football Association (Fifa) Gianni Infantino reacts strongly to the incident and calls it "absolutely disgusting and completely unacceptable" and writes on X, formerly Twitter, that Fifa may decide on harsher punishments for racism.
"All involved must act, starting with educating in the schools so that future generations understand that this is not part of football or society," writes Infantino.
"We must introduce automatic forfeiture for the team whose supporters have uttered racist slurs and caused the interruption of the match, as well as bans from all stadiums worldwide and legal action against racists."