Rangers boss Steven Gerrard admits he has an Old Firm selection dilemma after Steven Davis declared himself fit for Parkhead.
The Northern Irishman missed four games with a foot injury but made his return to action during the Boxing Day win over Kilmarnock.
The Light Blues suffered defeat to Celtic in the Betfred Cup final in the first of the games Davis sat out.
But since then the midfield trio comprising Ryan Jack, Glen Kamara and Scott Arfield have driven Rangers to Ladbrokes Premiership wins over Motherwell, Hibernian and Killie while also steering Gerrard's men to the Europa League point they needed against Young Boys to seal a place in the last 32.
But with Davis back in action, Gerrard admits he now has a tough decision to make as he prepares to face Neil Lennon's champions at Celtic Park on Sunday.
He said: "I want all my best players available. Steven had only trained for a couple of days, that's why we started with him on the bench against Killie.
"It was nice to get him on, he gives us a bit more control in the middle of the pitch. So I've got decisions to make between now and Sunday."
Alfredo Morelos climbed off the bench to notch his 28th goal of the season and seal the 1-0 win over Kilmarnock.
His 65th-minute winner came at the perfect time to ease the nerves of the anxious Ibrox support as Alex Dyer's side made life difficult for the hosts.
The Light Blues now head to the east end of Glasgow for this weekend's derby battle five points behind their bitter rivals with a game in hand.
"That's what Alfredo gets paid to do, he gets paid very well to do it," said Gerrard. "He's being doing it from the start of the season and I predict he'll continue to do it until the end of the season.
"We speak about him most weeks and most games because he is such a fantastic footballer.
"At Hibs, it was about Jermain Defoe, Ryan Kent and Joe Aribo. Today it's about Morelos.
"That's what being part of Rangers is all about, you expect your players in the final third to provide those moments of magic. He has stepped up at a big time for us."