The 5-1 win over Kilmarnock away from home came with a lot of positives. Firstly, when was the last time that we saw this version of Celtic? Free-scoring and relentless. The entire 25/26 season had felt more of a drag than a sprint.

Kasper Hogh's hat-trick would have restored the fans' confidence in the new signing after many had been left worried by his debut performance last week, as he missed a couple of sitters against Dundee FC.

Hogh made no such mistake today. And even though all three were simple goals, his positioning and link-up play had some real quality. The doubts may have been premature after all.

Benjamin Nygren continued to show his prowess in front of goal with another strike. Luke McCowan was also on the scoresheet.

It was not all sunshine and rainbows though. Alistair Johnston was taken off at half-time and lots of rumours cropped up after that. While most pointed at a possible injury, others thought that it was a sign that he was away following links to Everton.

Well, it feels like it is former and worryingly, Shaun Maloney could not confirm the extent of the matter. He just hoped that it was 'precautionary' and confirmed that he had 'felt something'.

.According to The Celtic Way, Maloney said: "He felt something. That was just precautionary, we hope.

"I thought the back four and the two in front, Callum (McGregor) and (Arne) Engels, were really good. Hopefully he's fine."

Considering Johnston's injury history, any issue is a reason to be worried. He spent two separate stints out injured last season.

Celtic do not have a quality backup option either. Colby Donovan came on at half-time but is he someone you can trust to be the regular starter at right-back if Johnston picks up another long-term injury or leaves?

READ MORE: Celtic ready move for Scotland's best player

There is no doubt that Johnston is an important part of this team. Most fans would prefer to see him stay rather than for the club to pocket a £10-15 million transfer fee from his exit. But an injury at this point in time would be the worst possible scenario.

Even if it does not turn out to be something minor and Johnston is back available, it should serve as a reminder to Celtic that they need to sign a quality backup option at both full-back positions.