McGregor limped off during the 2-1 midweek win over Motherwell at Easter Road feeling his hamstring, and Rherras could replace him in the back four with Efe Ambrose returning to central defence alongside Paul Hanlon.
After a goal on his debut, Flo Kamberi will likely continue up front for Neil Lennon’s men with Martin Boyle expected to partner him in attack.
After an impressive second half showing against Stephen Robinson’s side, Marvin Bartley stands a chance of replacing Vykintas Slivka in the starting XI.
If fit, Brandon Barker could slot into the Number 10 role once again. The on-loan Manchester City winger scored his first Hibs goal against ‘Well but was forced off with a knock in the second half.
Scott Allan will be pushing for a starting berth after sealing a return to Easter Road - he could come in if Barker doesn’t make it.
New signing Cammy Bell could find himself on the bench against his former club, while long-term absentees Steven Whittaker, Ross Laidlaw and David Gray are all out.
Rangers have a few injuries of their own to deal with. Graham Dorrans (ankle), Kenny Miller (achilles), Jordan Rossiter (calf) and Bruno Alves, Ryan Jack and Ross McCrorie (all knee) will miss out for Graeme Murty’s men.
Jason Cummings will almost certainly see some action against his old club - the striker had an impressive record of netting against Rangers while in green and white, and Lennon will be all too aware of his threat.
A win for Hibs would bring them within two points of the Gers, whereas the Ibrox side will be hoping for three points of their own to keep the pressure on second-placed Aberdeen.
Last five meetings: Hibs 1-2 Rangers; Rangers 2-3 Hibs; Rangers 2-3 Hibs; Hibs 3-2 Rangers; Rangers 4-2 Hibs.
Likely Rangers team (4-2-3-1): Foderingham; Tavernier, Martin, Bates, John; Goss, Holt; Murphy, Windass, Candeias; Morelos. Subs from: Alnwick, Hodson, Halliday, Docherty, Krancjar, Dodoo, Cummings, Herrera.
Likely Hibs team: (4-1-2-1-2): Marciano; Rherras, Ambrose, Hanlon, Stevenson; Bartley; McGeouch, McGinn; Barker; Boyle, Kamberi. Subs from: Dabrowski, Bell, Porteous, Slivka, S Allan, F Murray, Swanson, Shaw, Maclaren
Referee: Willie Collum
Odds: Rangers 97/100 Draw 5/2 Hibs 61/20 (Odds correct at the time of writing)