Miller has put pen to paper with the Gers for the third time and is set to be a first choice hit man for the Ibrox club next season.
And speculation is rife that his old strike partner Kris Boyd could join the Gers and line up alongside him in the SPFL Championship.
With Nicky Clark and Jon Daly already at the club, competition for places in the final third could be pretty stiff in the 2014/15 campaign.
And that could limit the number of appearances that youngsters like Gallagher, who made the breakthrough last season, get in the season ahead.
But Rangers youth supremo Gordon Durie is confident the teenager, who prefers to play up front, will still get his chance.
He said: "I think he has shown the manager what he can do in the games that he has played in the first team - and he will be involved again.
"Calum can play in a variety of positions and it is always useful having a player like that at a club. He offers the team a great deal when he plays."