Rangers hero Peter Lovenkrands has claimed the Gers will end Celtic's hopes of catching them at the Scottish Premiership's summit if they beat Neil Lennon's side at Ibrox on January 2 - but warned his former club can never afford to take their foot off the gas.
Steven Gerrard's men could go 19 points ahead of their Glasgow rivals if they repeat their 2-0 win at Parkhead in October on their own patch, a lead the Danish forward believes is unassailable.
But the 40-year-old, who lifted two league titles in Govan, admitted they cannot afford to give Celtic any hope of wrestling a tenth league title in a row back from the blue half of Glasgow - after being on the wrong end of a title collapse before.
Lovenkrands was a part of one of the most dramatic final days in the German Bundesliga, when Schalke 04 saw their dreams of a first title in 49 years fall apart with defeat at rivals Borussia Dortmund in 2007.
And while he is confident the same cruel fate will not befall his former club, he urged Gerrard's side to land a knockout blow at Ibrox to end any hopes of a Celtic turnaround.
He told BBC Sportsound: "I am going to say if Rangers win the Old Firm I do think they will win the league.
"But football is a funny game.
"You can never say never in football. We have seen crazier things happening and I have been part of it. My first season at Schalke we were 12 points clear with eight games to go and lost the title on the last day.
"I still have that in the back of my head."
He added: "First of all, there is a long way to go. Celtic are starting to get a bit of momentum now, they are starting to win games.
"They have some tough games in hand but if they win them they can claw it back to seven points.
"This game coming up, the Old Firm game, is huge - for Celtic most of all.
"They need the win. I think Rangers would be happy enough with a draw, if it ends a draw.
"Of course they would take the win, but if it is a draw I think it is worse for Celtic than it is for Rangers."
