Dedryck Boyata v Alfredo Morelos

The Belgian had a bomb scare afternoon when the teams met at Ibrox last month, being at fault for both Rangers goals and almost gifting them a third, but Celtic have lost only one goal in his four appearances since then. A big performance is required.

Morelos has 18 goals this term but only three have come against top-six rivals and he is yet to score against Celtic, although he should have done – he has racked up five sitters in the three previous derbies this season. He must show more composure when it matters.

Alfredo Morelos is still looking for his first goal against Celtic. Picture: SNS

Scott Brown v Josh Windass

Since Rangers won promotion to the Premiership they have allowed the Celtic captain to dictate the tempo and pace of the games – even Yuri Gagarin didn’t have as much space to operate in as the 32-year-old has enjoyed. No Rangers player has laid a glove on him so far.

Windass should be looking to change that. He has pace and physical presence but is guilty of disappearing from games for long spells. He scored the opening goal in last month’s 3-2 defeat at Ibrox, one of only three of his 17 goals which have come against teams from the top half of the table.

Moussa Dembele v Bruno Alves

The Frenchman is an enigma – a powerful predator in one game and then a ponderous plodder for the next two or three. That inconsistency – not helped by injuries, admittedly – has led to his re-sale value plummeting but he seems to thrive on the big occasion and he has six goals and three assists in eight games against Rangers.

Alves must find a way to stop him. The 36-year-old Portuguese has been reliable in the air but has often looked sluggish on the ground and, for a player who arrived in Scotland with a hard-man reputation, he has struggled to deal with physical opponents.

Three key battles that will decide Sunday's Old Firm semi-final