The 24-year-old has started all four competitive matches to date while the Light Blues await the end of a signing embargo on September 1 to complete the capture of Cameron Bell.
After coming through the club's youth ranks, Gallacher had to wait until this season to make his first-team debut for Rangers, having previously had loan spells with Cowdenbeath and Forfar Athletic.
Former Kilmarnock and Scotland keeper Bell is expected to come straight into the starting line-up when eligible while former Dundee and Everton goalkeeper Steve Simonsen is currently on trial at Murray Park with view to a permanent deal.
He told the club website: "All I can do is my best. That's all I've ever tried to do and if I catch the gaffer's eye, that's fair enough. If I don't, we'll see what happens going into September.
"I need to play games and if that's here, I'll be more than delighted as this club is huge but if it's somewhere else, then so be it.
"The last few weeks have been great. I've got my chance through circumstances but I've been enjoying it nonetheless."
Gallacher is confident manager Ally McCoist has been impressed by his form and hard work and added: "That's what I've got to do. Guys like Allan McGregor have had to do that in the past and it's all about concentration for them.
"He's someone who made a habit of pulling off wonder saves out of nowhere late in games and that's what I've got to be ready for too.
"Keeping your focus is part and parcel of football but hopefully the defence stays strong enough that I'm not called into action too much."