Niall McGinn has warned his Celtic team-mates that it is do or die in the SPL title race tomorrow.
Tony Mowbray's men travel to Ibrox (12.30pm) with their title dreams hanging by a very thin thread.
Seven points adrift of the Gers, Northern Ireland international McGinn knows his men are going into a must-win encounter.
Any slip-up could be fatal and McGinn will only be smiling at the finish if his side have shot down Walter Smith’s troops.
“It is massive game this weekend. We are seven points behind Rangers, but if we win it will be down to four and we want to keep the gap as close as possible,” said McGinn.
“It is a must-win game otherwise we will have a mountain to climb if we want to win the title.
“It will be a new experience for the new boys like Diomansy Kamara and Robbie Keane, but these types of games are made for players like them.”
McGinn is desperate to get his first taste of the white hot atmosphere of an Old Firm clash and he will have to shake off an injury to realise that dream.
“I picked up a bit of a thigh problem earlier this week, but hopefully I will be alright and available to play,” added McGinn.
“I was a sub in the last Old Firm game and I would love to be involved this weekend.
“Growing up as a Celtic fan these were the type of games you wanted to play in and I am sure it will be a great occasion at Ibrox.”
The build-up to the game has been dominated by discussions about match officials since an unknown Celtic source let it be known the club were frustrated with major decisions they believe had gone against them this season — including in the last two matches against Rangers.
Hoops chief Tony Mowbray has voiced his concerns about refereeing decisions to the Scottish Football Association, but insists it was not through any worries over bias.
“I would never question the integrity of any referee or question any bias,” he said.
“The game is becoming faster, particularly in Scotland. It is hurly-burly with long balls and
they have a very hard job to keep up with play and so I understand the problems they have.
“It is just a bit frustrating for us all and I'm sure it is for the officials who make the wrong calls.
“Whatever level you play, whether it's Champions League finals or Sunday league, you hope the big decisions are correct.”
Andreas Hinkel claims he and the rest of the Celtic team are relaxed about the match officials.
The former Stuttgart defender said: “I don't think there are any concerns about the referees in Scotland. Everyone can make mistakes, we can make them as well.
“The referees are only human and you can see it in Germany, or in every Champions League game or Europa League.
“They only give what they see and everybody can make mistakes.”
Mowbray also refused to reveal the injury that could keep Robbie Keane out of the game.
Mowbray added: “I am not going to tell you what Robbie's injury is, but he hasn't trained all week. I wouldn't want to say how big a blow it is or could be because we hope he will be fit, but we will wait and see.
“I will give the injured players as long as we can. They will have to train tomorrow and have no reaction when they wake up on Sunday morning, so we will wait and see.”
Aiden McGeady and Darren O'Dea return from suspension while Glenn Loovens has a chance after recovering from a hamstring injury.