A six-year-old Celtic fan applied to be the Scottish champions' new manager following Neil Lennon's resignation.
Aiden Headridge from Dundee wrote to the club following Lennon's exit ahead of Ronny Deila's appointment earlier this month.
However, his brother posted a copy of the club's response on Twitter, which read: "As you will know, we have appointed Ronny Deila as the new football manager.
"I believe Ronny has the knowledge, enthusiasm and confidence that is necessary to take the club forward and deliver continued success.
"I am really pleased to learn that you would like to be the Celtic manager and maybe one day that will happen. In the meantime, I hope you are enjoying school and are looking forward to the summer holidays."
The club also sent Aiden a new Celtic shirt.