Martin O’Neill was left with plenty to ponder after Celtic opened their Europa League campaign with a disappointing 3-1 defeat at home to Hungarian champions Ferencváros.
The visitors opened the scoring after 20 minutes when Bamidele Yusuf cut in from the right-hand side and sent a low effort towards the bottom corner to silence Celtic Park. His shot took a deflection off Liam Scales, with UEFA crediting it as an own goal.
Celtic responded impressively and levelled the tie just four minutes later. Kieran Tierney burst into the penalty area down the left after being slipped through by the lively James Forrest, before delivering a precise cut-back, allowing the unmarked Mika Baur to sweep the ball home from close range.
However, the hosts’ momentum was short-lived. Ferencváros restored their advantage in first-half stoppage time when chief tormentor Yusuf produced another dangerous run before finding captain Kristoffer Zachariassen, who finished with a clever back-heel from six yards.
Celtic faced an uphill battle after the interval and their task became even harder just two minutes into the second half. Yusuf again played a key role, sending a diagonal ball towards former Celtic winger Daniel Arzani, who cut inside from the left before unleashing a spectacular strike into the top corner.
The home side attempted a late rally, but the visitors defended their two-goal cushion and maintained their threat on the counter-attack, with Yusuf proving a constant menace for the Celtic defence.
We give each player a mark out of ten for their display.

1. GK - Viljami Sinisalo
This was as much a test of nerve as it was another look at his credentials to establish himself as Celtic's No.1 after being restored between the sticks following Sam Johnstone's Old Firm woes. No chance of keeping out Yusuf's defected shot from the edge of the box. Down well to his right to push Arzani's low shot away to safety and called into action again moments later to deny Gomez. Let Zachariassen's neat flicked finish creep under his body. Distribution was good overall but beaten three times. 5 | SNS Group

2. RB - Colby Donovan
Got off to a encouraging start but had his work cut out dealing with two attackers throughout most of the game as he Hungarians clearly looked to target the teenager. Needed some support and too often it wasn't forthcoming. Guilty of losing possession high up the pitch before Ferencvaros countered to make it 3-1 shortly after the restart. His work-rate cannot be questioned. 5 | SNS Group

3. CB - Cameron Carter-Vickers
Defended his box well for the majority of the game, although he had a part to play in the concession of Ferencvaros' second goal. 6 | PA

4. CB - Liam Scales
Not an evening he'll look back on with fond memories. Allowed Yusuf's effort to deflect off him and past his own keeper for the Hungarians' opener. Caught napping to allow Zachariassen to nip in front of him for the second goal. Sloppy in possession at times. 4 | SNS Group