The Scotland midfielder said: "We've got a great squad and that has probably been demonstrated over the last three or four games without Odsonne.

"He is such a big player for us at home and in Europe but Lewis has stepped up and scored the goal against Rennes.

"We've got loads of strength and depth in the squad and whoever is asked to play up front on Sunday, I'm sure they'll do a job for the team.

"You can tell Lewis is an intelligent footballer. Normally these guys with the brains to play anywhere on the pitch.

"It was great for him to come in, get his start and his goal last week and you can see he's full of confidence and got his assist last night with his wee flash across the box.

"He's been great since he came in and it's another boost for the team to show that when boys come in they are ready to play."

Griffiths is still to rediscover full sharpness after a prolonged spell out battling injury and personal problems.

But McGregor would have no doubts about plunging him into action against their bitter rivals.

He said: "Leigh will be definitely champing at the bit too. Obviously with all the big games you are desperate play. Even last night was another step forward for Leigh, he looked a bit sharper again when he came on and helped us to get the winning goal.

"He'll be desperate to play, as will everyone in the squad. It's just important that we get as many players right at it leading into the weekend.

"Leigh has missed a lot of football so the more he can get on the pitch it will be beneficial for him and for the squad too. Getting a fully-fit Griffiths back will only help Celtic.

"I think he's getting there, if he's asked to play I don't think there will be any problem."

Celtic have a huge carrot dangling over the National Stadium this weekend as they eye up a potential 10th straight trophy triumph but the motivation is just is great for Gers as they look to lift their first major prize since 2011.

The Hoops warmed up for Sunday's showpiece with the exhilaration of a stoppage-time win over Hamilton while Gers threw away two points at Pittodrie as they allowed Aberdeen to come from two goals down to snatch a draw.

Lennon's team have now stolen two points ahead in the Ladbrokes Premiership title race but McGregor thinks Gerrard's team will have forgotten about their slip-up come the weekend.

He said: "The psychological effect was big for us getting that win. We've been on a great run and to continue that was great and takes us nicely into the weekend.

"We didn't know what was happening at Pittodrie for definite but you can hear the noises in the stadium so it started to filter round after half-time.

"But we just look after our stuff. We had a couple of chances to make it 2-0 but never got there. Once Hamilton scored panic stations set in a wee bit but thankfully we got the winner.

"I don't think (Rangers will be feeling down after their result at Aberdeen). The league is completely separate to cup finals. Form goes out the window and the team that plays the best on the day wins normally.

"It's just important we take our confidence into the game and make sure we earn the right to win."