"I can tell you tonight that Izak Rankine's season is over," McGuire declared on Footy Classified following a lengthy investigation by the AFL Integrity Unit.
McGuire reported that the AFL had sent the Adelaide Crows a letter on Tuesday evening informing them of their intention to suspend Rankine for five games as sanction for a homophobic slur directed at a Collingwood player last weekend.
That would mean Rankine would miss the 2025 Grand Final if Adelaide to qualify, or the start of the 2026 season if they are eliminated prior.
Adelaide and Rankine will have the opportunity to appeal the suspension on Wednesday morning, according to McGuire.
It comes just weeks after West Coast's Jack Graham was given a four-week ban for directing the same slur at a GWS opponent earlier in the season.
It is understood that Rankine phoned his Collingwood opponent on Sunday to apologise, whilst teammate Taylor Walker told Triple M radio on Tuesday that Rankine is "very remorseful" and "will accept whatever comes his way".
An official announcement is expected to be made by the AFL on Wednesday morning.