Rangers host Celtic in the fourth round of the Scottish Cup at Ibrox on Sunday.
The newly-crowned Premiership champions will look to knock out the four-in-a-row holders as they seek a league and cup double under Steven Gerrard.
Here, the PA news agency looks at some of the key talking points ahead of the match.
Celtic need to end Rangers' 100 per cent Ibrox record
Rangers are 20 points clear of the deposed champions with four league matches remaining and their unbeaten status in the league and Scottish Cup this season owes much to their home form.
The Light Blues have won all 17 league games and one Scottish Cup tie at Ibrox, scoring 53 times and conceding just three.
If Celtic, under interim boss John Kennedy, are to find a way into the next round they will have to end Rangers' domestic dominance in Govan.
But Celtic should have no fear, should they?
Kennedy recently claimed that Celtic on their day are the best team in Scotland, a comment which did not go down well at Ibrox.
But as Rangers took encouragement from their performance in the narrow 1-0 League Cup final defeat to the Hoops at Hampden Park in 2019 – their last defeat by Celtic – the visitors will look to the most recent two Old Firm games for succour.
Celtic had the best of the 1-1 draw at Parkhead in March and the 1-0 defeat at Ibrox in January, matches which belied the points gap in the table.
And following the morale boosting 6-0 win over Livingston at the weekend, Celtic will go into the game with belief and confidence as they look to take the next step towards winning the trophy for a fifth successive time.
Gerrard admitted performances have slightly dipped in comparison to the title run-in but is confident that the magnitude of the game will see his side hit top form.
Fitness issues
Kennedy will give James Forrest every chance to prove his fitness.
The 29-year-old recently returned to the Parkhead side after a lengthy spell on the sidelines after ankle surgery.
However, a tightening of his back and hamstring during the 6-0 win over Livingston last Saturday – where he scored his second goal in two games – saw him replaced just before the hour mark.
He will undergo treatment all the way to Sunday with Celtic fingers crossed that he comes through.
Rangers captain James Tavernier has been key to the Light Blues' success but has not played in two months due to a knee injury.
However, there were some encouraging noises coming out of the Ibrox club on Friday and like Forrest, the Gers full-back will be given every chance to make it.
Who needs the win most?
📸 GALLERY: Old Firm Preparations
👉 Check out the full training gallery: https://t.co/L7nMdN7pR0 pic.twitter.com/XpJOLsR16B
— Rangers Football Club (@RangersFC) April 16, 2021
Celtic have had an horrendous season.
Their bid for a 10th successive title was ended by Rangers, the League Cup left the Parkhead trophy room too and the resignation of manager Neil Lennon has the Hoops on the hunt for a new boss.
Winning the Scottish Cup for a fifth successive time would see Celtic's season end on a high.
After preventing their city rivals reaching the coveted 10 to win the league for the 55th time the pressure is off Rangers to an extent.
However, another cup exit in the Betfred Cup to St Mirren was a blow to Gerrard, who has yet to win a cup competition and he and the players will be determined to complete a league and cup double.
Taking Celtic out the equation will go a long way to doing that. Both clubs have their reasons for winning, Sunday will reveal their levels of determination.
