Scott Allan believes Saturday night's game at St Mirren is a must-win for Rangers if they're serious about challenging for the title.

Rangers can pile pressure on Celtic, who play Kilmarnock on Sunday, by narrowing the gap at the top to one point with victory in Paisley.

The Ibrox side have failed to win on three of their past four trips to face the Buddies. And while Rangers are in fine from with nine wins in an 11-game unbeaten run, they have drawn half of their six Premiership away matches this season.

Speaking on the BBC's Scottish Football Podcast, former Hibs, Celtic and Dundee United midfielder Allan said: "If Rangers are serious about putting a real title challenge up then these are the sort of games they have to go and win.

"A few weeks ago at Dens Park, Dundee basically dictated how Rangers played in the first half.

"So Rangers will be looking at trying to right that wrong but for St Mirren, I think they would have to get everything right on the night to get something from Rangers."

Allan believes Rangers are set to "click" at the top end of the park and thinks St Mirren have to score the opener if they are to stage an upset.

"Going forward, Rangers look they're just about to click into gear," he said.

"I think Badredine Bouanani coming into the team has brought something different, he's got that eye for a pass and we've not seen that in a Rangers team for a while.

"St Mirren would have to be all but perfect for me and I just feel it'll be a difficult one for them. They would have to score first."