Manager Ange Postecoglou criticised Celtic’s work rate as they cruised past Raith Rovers into the Scottish Cup quarter-finals.
Liam Scales’ stunning strike gave the Glasgow side a first-half lead.
But Celtic were below par until Giorgos Giakoumakis and Daizen Maeda scoring in quick succession and Nir Bitton scored on the rebound from his late, saved penalty.
“I think the urgency wasn’t quite there,” Postecoglou told BBC Scotland.
“It’s not about singling out individuals. We have an intent and ambition to be a certain kind of team, training is intense, so game-day we are intense no matter who starts.”
There was further good news for Celtic with centre-half Christopher Jullien making his comeback after a 13-month injury lay-off.
Postecoglou’s side will find out their opponents in the last eight on Monday following the tie between Peterhead and Dundee.
In their last three games, Celtic had been adept at taking the game to their opponents early on, with eight of their 10 goals being scored before half-time.
They set their stall out early against John McGlynn’s Championship visitors, with Mikey Johnston and Bitton shooting over and Rea Hatate drilling a shot into the hands of goalkeeper Jamie MacDonald.
Scales broke Rovers’ resistance when he opened up his left foot and cracked a shot in off a post.
Celtic were fortunate not to concede a penalty when a bouncing ball appeared to hit the arm of defender Cameron Carter-Vickers, but Rovers’ appeals were dismissed by referee Steven McLean.
There were other nervous moments in Celtic’s box as the Fifers committed men forward, but the visitors struggled to get a meaningful shot on target and goalkeeper Joe Hart was a virtual spectator.
Giakoumakis hit the crossbar, but it would not have counted with Johnston already flagged for offside.
Celtic had hit a lull before Jota’s introduction gave them a lift, the winger creating a chance for Tom Rogic before he was instrumental in Giakoumakis making it 2-0.
The Greek striker timed his run to beat the offside trap and knocked in Jota’s inch-perfect cross.
Soon, it was three when Maeda got to a corner. MacDonald made a great save initially but could only knock it off the Celtic man and back over the line.
A controversial penalty made it four when Sean Mackie was harshly penalised for handball. Bitton bundled it home after his first effort was saved by MacDonald, with the 4-0 scoreline a touch harsh on Rovers.
Man of the match – Liam Scales
What they said
Celtic manager Ange Postecoglou: “We weren’t great in the first half. We didn’t work hard enough, we didn’t play at a tempo, took too many touches of the ball. The second half was better.
“We made seven changes to the team, so you know it’s not going to be as fluent or as cohesive.”
Raith Rovers manager John McGlynn: “I thought we were very well organised and disciplined in our play. We knew Celtic would come out the traps and bombard us early on and we wanted to get beyond that period, which I thought we did.
“There was a claim for a penalty, but I haven’t seen it back. I am proud of the players and we have to get our league campaign going again.”
- 20Carter-VickersSubstituted forJullienat 74′minutes
- 18RogicSubstituted forIdeguchiat 69′minutes
- 49ForrestSubstituted forAbadaat 69′minutes
- 7GiakoumakisSubstituted forMaedaat 69′minutes
- 19JohnstonSubstituted forNeves Filipeat 55′minutes
- 17Neves Filipe
- 6BenedictusSubstituted forMackieat 80′minutesBooked at 83mins
- 20WilliamsonSubstituted forZanattaat 45′minutes
- 7ConnollySubstituted forVarianat 64′minutes
- 8MatthewsBooked at 87mins
- 22RossSubstituted forArnottat 85′minutes
- 9GullanSubstituted forPoplatnikat 64′minutes
Match ends, Celtic 4, Raith Rovers 0.
Second Half ends, Celtic 4, Raith Rovers 0.
Offside, Celtic. Reo Hatate tries a through ball, but Liel Abada is caught offside.
Foul by Christopher Jullien (Celtic).
Matej Poplatnik (Raith Rovers) wins a free kick on the left wing.
Goal! Celtic 4, Raith Rovers 0. Nir Bitton (Celtic) right footed shot from the centre of the box to the centre of the goal following a set piece situation.
Penalty saved! Nir Bitton (Celtic) fails to capitalise on this great opportunity, right footed shot saved in the bottom right corner.
Ross Matthews (Raith Rovers) is shown the yellow card for hand ball.
Attempt blocked. Jota (Celtic) right footed shot from the left side of the box is blocked.
Penalty conceded by Sean Mackie (Raith Rovers) with a hand ball in the penalty area.
Nir Bitton (Celtic) wins a free kick in the attacking half.
Foul by Ross Matthews (Raith Rovers).
Substitution, Raith Rovers. Aaron Arnott replaces Ethan Ross.
Sean Mackie (Raith Rovers) is shown the yellow card for a bad foul.
Daizen Maeda (Celtic) wins a free kick on the left wing.
Foul by Sean Mackie (Raith Rovers).
Foul by Daizen Maeda (Celtic).
Dario Zanatta (Raith Rovers) wins a free kick in the defensive half.
Substitution, Raith Rovers. Sean Mackie replaces Kyle Benedictus because of an injury.
Substitution, Celtic. Christopher Jullien replaces Cameron Carter-Vickers.