Celtic fans are sweating over the fitness of Alistair Johnston after the Canadian right-back was substituted at half-time during the Champions League clash against Dinamo Zagreb. With the League Cup final against Rangers just five days away, concerns will be over his availability for the massive showdown at Hampden.

Johnston picked up a knock in the first half, and while the exact severity is unclear, his substitution at the interval for Anthony Ralston is enough to raise eyebrows. The Canadian is known for his durability and grit, so it’s unlikely he would come off unless he felt he had to or Brendan Rodgers decided it was best to protect him with Sunday in mind.

The full-back has been a vital cog in the Celtic’s system, offering defensively and, in the final third, partnering Nicolas Kuhn down the right. Losing him for the final would be a significant blow, not only because of his quality but also the leadership he provides on the pitch.

Anthony Ralston is a capable replacement, but the prospect of facing Rangers without the first-choice right-back would undoubtedly be a concern for Rodgers. At this stage, it is difficult to gauge whether Johnston’s withdrawal is purely precautionary or indicative of something more serious.

Updates on Johnston’s condition are likely to follow post-match, but for now, speculation will dominate. Celtic fans will be hoping it’s nothing more than a minor issue and that their defensive stalwart will be ready to step out at Hampden on Sunday. For now, all eyes remain on how the situation unfolds.