On-loan Ipswich midfielder Jonny Williams has returned to parent club Crystal Palace for treatment on a groin injury.
Rotherham manager Steve Evans has confirmed the potential loan exit of defender Kirk Broadfoot fell through this week.
Former Sunderland midfielder Rae played alongide Ince at Wolves before working as part of his backroom team at MK Dons and Notts County.
The 43-year-old ex-Dundee player manager had been working with the Dons as a chief scout and joins Steve Thompson in assisting Ince, who lost his first game at the helm against Leeds on Wednesday night.
Ince told BBC Radio Lancashire: "He's got a vast amount of knowledge, which he can lend to the players and the rest of the staff.
"He's now part of the team alongside Thommo."