On social media, Tierney shared his appreciation for the club and its fans, saying: “I would like to thank everyone at Arsenal from the very beginning. They have supported me and the team during good times and bad times, and I'm particularly grateful for their support during my difficult times.
“I think it's the times when things weren't easy that they supported me the most. I'm very thankful for that, and I feel lucky to have had their support. The love and support from the fans have been amazing, and I've enjoyed every moment of my time at the club.
“I've learned a lot, improved a lot, and I feel grateful to have played for such a great team. I'm looking forward to the next chapter of my career with Celtic."