The 22-year-old Scotland striker made his switch to the City Ground last summer but found himself sidelined by Mark Warburton during the final days of his Forest reign.
The Light Blues are now rumoured to be considering offering him an escape route back north of the border.
A fee of around £1 million would be required to prise him away but Ibrox boss Graham Murty now has room to manoeuvre after striking a deal with Mexican outfit Cruz Azul - now managed by his Rangers predecessor Pedro Caixinha - that will see them cover all of Carlos Pena’s £20,000-a-week wages as part of a six-month loan deal, with a guaranteed £2 million sum to follow if the move is made permanent.
However, it is understood that Cummings is not ready to walk away from Forest just six months after joining from Rangers.
He is willing to bide his time while Karanka, who was handed a two-and-a-half-year deal by Forest chiefs on Monday, assesses his new squad in the hope he can make a bigger impact under the former Middlesbrough boss than he managed with ex-Rangers manager Warburton.
While Pena has agreed terms with Cruz Azul, it is believed that Fabio Cardoso and Eduardo Herrera - fellow Caixinha signings - will only be allowed to move themselves if they can find clubs also willing to pay their salaries in full.