A Competition Committee judge on Wednesday ordered the sanction having studied the case after Pique was sent off for the offense during the match.
Barcelona presented arguments in defense of its player, but was unable to shorten the punishment, and the decision means Pique will not be able to play against Bilbao, Malaga, Atletico Madrid and Levante at the beginning of the La Liga season.
Referee Velasco Carballo's match report said Pique used foul and abusive language while shouting at the assistant referee.
Earlier, Pique had apologized and insisted he did not insult the official.
Pique said it was a match with a lot of pressure "in which we were playing for a title."
Related story
Barca defender Pique extends contract until 2022
