The US membership tried to signal Rooney final summer season when he left Manchester United however he determined to finish an emotional return to Goodison Park as an alternative.
Hopes were high for the former England captain's second coming at Everton when he moved from Manchester United last summer, but despite and initial burst of goals, they have since dried up.
He made his Premier League debut for Everton at just 16 and has posted nearly 500 appearances for Everton and Manchester United across competitions, plus 119 for England.
The 32-year-old has scored 11 goals across all competitions with the Toffees in 2017-18, but is believed to be keen on a departure.
Earlier in the week, we learned that Rooney's camp had held "serious talks" with DC, which in turn have lead to a deal being struck "in principle" between the two parties.
"If Wayne's time is up at Everton, there's no reason why Rangers shouldn't put their name forward", Gray told talkSPORT host Jim White on Tuesday.
There have been troubles on and off the field at different times in his career - both with Manchester United and England - but he was nearly always the first name on any England team-sheet for managers from Sven-Goran Eriksson to Roy Hodgson.