Celtic survived a scare from Conor Sammon to make it Into the last 16 of the Scottish Cup but landed Ange Postecoglou with another trio of injury worries.
Goals from Giorgios Giakoumakis and Liel Abada before the break appeared to put the visitors on easy street against a well-organised Alloa outfit but Barry Ferguson’s men struck with 15 minutes left to make it more nervy than it should have been.
And when the dust settled, the Hoops boss was left sweating over the loss of Callum McGregor, Yosuke Ideguchi and Abada, all of whom went off injured.
Postecoglou made six changes from the side that beat HIbs on Monday but he still fielded a strong line-up against an Alloa outfit currently lying eighth in League One.
Giakoumakis led the line either side of Abada and Daizen Maeda but Reo Hatate, who had such a fine debut against HIbs, was on the bench, alongside Christopher Jullien, making his first squad appearance in 13 months after suffering cruciate ligament damage.
Ferguson’s side were massive underdogs but had Premiership experience at both ends of the pitch in the shape of Mark Durnan and Sammon.
The Indodrill Stadium was bursting at the seams with a crowd of 3022, as Alloa kicked off and within two minutes they gave their fans hope with an audacious attempt from distance by Mouhamed Niang, who robbed Tony Ralston and attempted to chip Joe Hart.
The ball floated a couple of feet over the keeper, who was stranded miles off his line.
As expected, Celtic dominated possession but they hadn’t troubled Alloa until they struck ruthlessly in the 13th through Giakoumakis.
The Greek striker darted to the near post to cleverly divert Liam Scales’ left wing cross past David Hutton.
The concession was a bitter blow to the hosts but they dug deep to keep Celtic from inflicting further damage immediately.
The visitors, for all the possession enjoyed, still struggled to make Hutton work until the half hour when he had to keep out efforts from Tom Rogic and Maeda in quick succession.
And 10 minutes from the break, Celtic had Hart to thank for keeping them ahead.
The keeper had been redundant but reacted quickly to block Sammon’s powerful drive with his leg as the striker latched onto a Steven Boyd flick.
Celtic suffered an injury blow just before the break when Callum McGregor took a heavy blow to the face in an aerial duel with Adam King. The Hoops captain was replaced by James McCarthy.
But it didn’t disrupt them too much, as Abada doubled the lead in the time that had been added on for McGregor’s injury.
The young Israeli took took it magnificently, cutting in from the right and curling a left footer into the corner from 18 yards.
It was a hammer blow to Alloa and gave Celtic the cushion they wanted.
Abada almost beat Hutton again within a minute of the restart, his sliced cross having to be clawed out from under the bar by the keeper.
The Israeli’s fine evening’s work ended in the 53rd minute when he hobbled off with an ankle injury, to be replaced by Jota.
And within minutes the Portuguese had produced a peach of an ins-winging cross for Maeda to force Hutton into a fine low save.
The injuries continued to pile up, though and Ideguchi was next to suffer after a challenge from Niang that earned the Alloa midfielder a booking. Nir Bitton replaced the Japanese midfielder.
The traffic continued to flow towards the Alloa goal and Giakoumakis and Maeda were guilty of glaring misses.
And they were made to pay 15 minutes from time when Alloa halved the deficit through Sammon, who rose highest to head past Hart after sub Jon Robertson had crossed in from the right.
They had a chance to take into extra time in the last minute but Alan Trouten fired over and Alloa were out, but not without a fight.
3 talking points
Walking wounded
A comfortable afternoon for Celtic, who were never in trouble until Sammon made it interesting, but the injuries keep on coming and the manager will be hoping that the knocks suffered by McGregor, Ideguchi and Abada aren’t too serious.
Up like a Sammon
Alloa were limited but gave themselves hope with Connor Sammon’s header, which was revenge on Joe Hart for his fine first half save at 1-0.
Not quite a Greek tragedy
Giorgios Giakoumakis would have been delighted with his goal but the Greek should have been going home with the match ball, having missed a couple of great chances. Still, it’s more minutes in his legs as he tries to make a belated impact in Scotland.
