Will fan factor work for or against Rangers?

How big a factor will the Ibrox crowd be in Sunday's Old Firm showdown?

With no away fans in attendance, Rangers will be backed by 50,000 supporters in the League Cup last-eight tie against Celtic.

But that could turn out to be a help or a hindrance.

Speaking on the BBC's Scottish football podcast, Ewan Murray - The Guardian's Scottish football correspondent - explains: "The 50,000 Rangers fans element is interesting because Ibrox for a home player can be a difficult place to play when things are not going for you.

"And if Rangers don't start this game well with only their own fans there, it will become tricky. There's no doubt about that. If Celtic score the first goal, it becomes very, very difficult for the Rangers players.

"The the flip side of that, of course, is obvious. If Rangers start well and get the opening goal with all those fans behind them they will feel they're they're in a good place.

"I think this game will come down to the strikers. Celtic have more firepower, but going by Martin O'Neill's comments on Wednesday night, he's a bit exasperated with the way they're playing in front of goal."

Former Celtic midfielder Scott Allan, meanwhile, believes "anything can happen" in the sides' first meeting of the season.

"I think Rangers will look at Celtic the other night and see, as much as they did create chances, St Johnstone were able to play through them quite comfortably," said Allan.

"And Celtic will look at that the Rangers game and see St Mirren at times really caused them problems, were dragging Emmanuel Fernandez all over the place at times.

"It's a really hard one for me to pick a winner based on what I've seen over the last week. It could go either way, but ultimately it could come down to which player can produce a big moment."