A five-year-old Celtic fan rang the club to apologise for missing a game after it clashed with a friend's birthday party.
Louis Kayes, from Moodiesburn in North Lanarkshire, called the club to tell them he was sorry he had not made it to Saturday's game against Motherwell.
The boy's mother, 35-year-old Lisa Kayes, said he had borrowed her phone to make the call.
She told the BBC her son had called after a "bit of a guilt trip".
Speaking on BBC Radio Scotland's Kaye Adams programme, she said: "He was in the living room with my phone and then I heard the voicemail message from Celtic Park saying 'thank you for calling'."
Ms Kayes said Louis wanted to speak to the club's manager, Brendan Rodgers, and his favourite player, Celtic captain Scott Brown, to apologise and explain his absence.
"He wanted to let both of them know he'd missed it in case they were looking for him," she said.
Louis told BBC Scotland the birthday party had been "good", but said he would definitely not be missing Wednesday evening's Champions League clash with Borussia Monchengladbach.
He predicted a 3-1 victory for his club, but confessed to feeling some pre-match nerves.
Ms Kayes added: "He's possibly the most passionate five-year-old I know in terms of supporting Celtic. He doesn't like to miss a game.
"I think Celtic-Motherwell is the last home game he'll miss in a while. I don't think we'll be getting him to many other things on a Saturday afternoon."