The Newcastle United pair spent this season on loan at the League Two club.
And Carlisle manager Keith Curle has already spoken to the Gillead and Gillesphey, both 20, about returning to Brunton Park.
"I have already spoken to those players and their agents," Curle told the Carlisle News & Star.
"I see their continued progression to have a minimum of another six months with us, or potentially another year with us.
"Because of what they’ve done and how they’ve adapted to league football, that option might be taken away from us.
"I've expressed an interest with the players and ultimately it's down to them.
"But they can't afford to be at their parent club and not be playing games. I don’t see them progressing if they're not playing football."