Rankine is set to be the sixth AFL-listed player suspended for a homophobic slur against an opponent in the past 16 months.
The Crows star has admitted directing a homophobic slur to an unnamed Collingwood opponent in Adelaide's three-point win last Saturday night.
The 25-year-old apologised to the Magpie player on Sunday as the AFL's integrity unit launched an investigation.
The club is awaiting a decision from the AFL, which is expected on Thursday.
The AFL is believed to have settled on a five-match ban which would rule Rankine out of ladder-leading Adelaide's looming finals campaign.
The Crows were given until late Wednesday to respond, with the club seeking a lesser suspension that would give the 25-year-old a finals lifeline.
Adelaide play North Melbourne on Saturday in the last home-and-away round and will then host two finals.
Last month, West Coast's Jack Graham was banned four games for a homophobic remark to a GWS player.
In April last year, Port Adelaide's Jeremy Finlayson was suspended for three games and, the following month, Gold Coast's Wil Powell was suspended five matches, both for directing homophobic slurs at opponents.
Two VFL players have also been banned for the same offence.
Sydney defender Riak Andrew last month was suspended for five matches for an anti-gay slur while playing in a reserves game against North Melbourne.
And in July last year, St Kilda's Lance Collard was banned six games for homophobic comments while playing in the VFL for Sandringham against Williamstown.