The NRL's most prominent Indigenous superstar failed to train at 16th-placed Souths' final session for Saturday's clash with Parramatta, but could return next week.
Mitchell suffered the injury in last week's win over Gold Coast and will be replaced at centre by Bayleigh Bentley-Hape, bringing Tyrone Munro onto the wing.
"(Mitchell) is not mobile enough, hopefully next week," said coach Wayne Bennett.
"He played last week and it was Indigenous Round last week as well. We're disappointed he's not playing."
It's a frustrating blow for Mitchell, who had only returned from a quadriceps injury last week.
"You can be sad about it, you can be anything like about it. The bottom line is he's not playing and he's not fit to play. That's it," Bennett said.
Mitchell joins Campbell Graham, Cameron Murray, Keaon Koloamatangi and Tevita Tatola in a star-studded casualty ward, but Souths have Cody Walker back from a hamstring injury.
The veteran participated in light training on Friday and will return from a seven-week lay-off via the bench, while the Eels could have superstar rookie Isaiah Iongi back from a fractured hand.
"He'll have a fitness test tomorrow (on game day) and we'll see how he goes," Parramatta coach Jason Ryles said of his fullback.
Superstar Rabbitohs winger Alex Johnston is an outside chance to break the NRL's try-scoring record this weekend, requiring four four-pointers to pass Ken Irvine's mark of 212 tries.
The record has stood since 1973, so long ago that rugby league stalwart Bennett never saw Irvine play, confined to listening to the North Sydney and Manly winger on the radio from his home state in Queensland.
Bennett would not weigh into speculation fans could rush the field when Johnston finally passes Irvine, with Indigenous Round shaping as a fitting occasion for the Koedal Klan Saibai Man.
"That would be special but it's going to be special anyway," Bennett said.
"I don't know (how it'll be celebrated), I want to get him there and we'll worry about the party after."
Souths' only home game at Allianz Stadium for the year comes some two months after the NSW Government formally rejected their push to relocate the majority of home games there from 2026.
The Rabbitohs have been permitted to host at the $828 million Moore Park venue for Indigenous Round, but have been told breaking their contract with Accor Stadium would be too costly for the taxpayer.
The club is intent on keeping up the fight, with Bennett saying the Eels clash and an away game in round 27 would give fans a chance to show how much a move to Souths heartland would mean.
"It'll give everybody a pretty fair indication of what it would mean to the South Sydney supporters," Bennett said.
8°C