Celtic have been knocked out of the Viaplay Cup, losing 1-0 to Kilmarnock at Rugby Park.

In Brendan Rodgers’ first cup tie since returning as Celtic manager, he lost his 100 per cent record, in what was a poor performance from the cup holders away from home against a resolute Kilmarnock side, who deserved their win.

Summer signings Gustaf Lagerbielke and Odin Thiago Holm were given their first competitive starts for Celtic, the latter making his full debut for the club following his move from Elfsborg earlier this week. 

After a largely uneventful first half, the game sparked into life when the hosts took the lead through Marley Watkins. Celtic tried to push for an equaliser, but it never transpired and Celtic were put to the sword by the home side by a single goal.

With that being said, here are the key points of discussion from this afternoon's game at Rugby Park...

READ MORE: 'It's not the same squad' - Brendan Rodgers on Celtic defeat

Lethargic performance

No two ways about it, Celtic did not play well today. A totally disjointed performance, the team looked uninspiring and lethargic for large portions of the game. A team very much in transition in terms of the way they set out to play, key members of the squad have struggled to revert back to the way Rodgers wants his side to play, and it showed today. McGregor, Anthony Ralston and Greg Taylor are clearly struggling to adapt to Rodgers’ ideas thus far. Celtic have failed to replace key players such as Jota and Aaron Mooy this summer but had gotten away with it against Ross County and Aberdeen. This performance today indicates that further business must take place in the transfer window, although you could argue this should have been done far earlier in the window in all honesty. The regression in Celtic’s tempo and intensity is alarming, a far cry from the swashbuckling football that the side showed under Ange Postecoglou last season. Plenty to work on for the returning manager, but a really poor performance from Rodgers’ men, in what was an alarming afternoon for Celtic and their manager. The honeymoon period - if there was one - is certainly over now for Rodgers and Celtic.

Ryan McGinlay

McGregor's struggles

It's fair to say that Celtic's captain fantastic McGregor is not fully functional and operational this season. The skipper seems to be getting caught in possession far too often than he has ever been at any stage in his Hoops career. Once it clicks into gear and it hasn't yet he will be the difference maker. He is critical to how the manager wants his Celtic team to play. There is also the argument that he is better deployed further up the pitch. He does look isolated at times in the new Rodgers style and looked sluggish at Rugby Park but he was not alone. McGregor has set such a high bar of consistency that it tends to get noticed when he falls way below it and so far this season that has been the case.

Tony Haggerty

New-look defence

Celtic’s backline had a new look to it, with summer signing Maik Nawrocki being joined by Lagerbielke in the centre of defence. In what was always going to be a difficult game – especially on a plastic pitch – the two acquitted themselves well for the most part. Nawrocki had a shot early on in the game which went well wide. In terms of his passing, Lagerbielke opted on more than one occasion to ping the ball to Daizen Maeda out on the wing, which found its target more often than not. Not afraid to get stuck into the physical side of proceedings, the Swede put himself about, in what was a fascinating battle between himself and Kilmarnock attacker Marley Watkins. Despite being paired together for today’s game, it will be interesting to see who is elected to start alongside Cameron Carter-Vickers when the American is fit enough to return to the team, as you would expect the two starters to be competing for the other defensive spot that Carl Starfelt has vacated. Despite the two defenders both having solid enough games, they both found themselves on the losing side, which they will be disappointed with. 

Ryan McGinlay

READ MORE: Celtic's Brendan Rodgers' full Q+A as manager bemoans side

Holm fails to take his chance

All eyes were on Odin Thiago Holm as he made his first start under Rodgers after a string of impressive cameos both in pre-season and league matches. He was well shackled by impressive teenager David Watson in the Kilmarnock midfield and he had a real stop/start game. There is a footballer bursting to get out as he attempted the risk forward pass more often than not but many failed to find their intended target. Whilst Rugby Park is not the easiest surface to conquer there is no doubt that Holm did not have the impact on the proceedings that he or his manager craved which will have been a major disappointment to all parties concerned. It was no real surprise when he made way for David Turnbull on 65 minutes.

Tony Haggerty

Cup record is gone

There was a distinct lack of guile, craft and ingenuity in the final third where it mattered most for Celtic. Kyogo Furuhashi had two efforts at goal and Matt O'Riley sidefooted tamely into the goalkeeper Will Dennis arms in the opening 45. When the hosts got their noses in front the holders didn't even look as if they were capable of mustering a shot or fashioning a clear-cut chance although Yang ought to have restored parity with nine minutes left on the clock. Rodgers' proud record of winning seven out of seven trophies from his first spell in charge of the Hoops is now over and ended in ignominy at Rugby Park as his charges served up a woeful display which saw them get what they deserved from the cup contest.

Tony Haggerty