McGuire was on Tuesday night found guilty of the serious charge for the second time this season, after attempting to deny the accusation in a lengthy hearing.
The Warrington forward's ban comes after he was also suspended for seven matches following a pre-season testimonial match in which was found guilty of making a derogatory slur regarding people with a disability.
Both offences have come against Leigh and been graded at the most serious 'F-level' charge.
McGuire signed for the Wolves on a two-year deal in late 2022 but there are now serious questions over whether he will see out his first 12 months.
He has played only seven matches for the club, and now twice attracted negative headlines while leaving them short on the field.
If he is retained, the 33-year-old will only return late in the season, depending on how many games Warrington survive in the Challenge Cup.
McGuire endured a horror judiciary record in his final years in the NRL but no charges in Australia had related to offensive language.
He missed 10 games in bans from five separate offences in the 2021 season alone at St George Illawarra, having been hit with another five charges in the two years before that.
It prompted him to admit he needed to clean up his act last year, avoiding any further suspensions after missing the first five rounds due to a ban incurred in the previous season.
McGuire had maintained his innocence on the first of the charges from February, and insisted last month he had not uttered a derogatory slur.
"I'm disappointed with the way it all went," he told The Mirror last month.Â
"A few words went back and forth. From both sides. And I said some nasty stuff. But I never said that. It was heat-of-the-moment stuff."
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