There's a lot of excitement surrounding Kieran Tierney at Arsenal.

The left-back made his debut for Celtic in 2015 and quickly emerged into one of the best players in the Scottish Premier League.

After much speculation, Tierney finally mad the move to Arsenal on transfer deadline day as he completed a £25 million move.

Unfortunately, the 22-year-old is yet to make his first appearance for the club as he is still recovering from a hernia.

But he participated in his first training session for his new club on Thursday, where he nutmegged Shkodran Mustafi.

While being a talented footballer, Tierney also has a likeable personality.

He was a fan-favourite at Celtic before making his move and he's shown why that was the case with a lovely gesture to a young Arsenal fan.

According to the Sun, a 15-year-old Arsenal fan by the name of Jack Staniard had his club shirt burned by bullies.

So what did Tierney do? He went out of his way to send him a signed replacement with his name and number on the back.

He also left Jack a touching letter. 

“Dear Jack, I understand that you have been through a tough time recently and experienced things most people don’t," he wrote.

“That must have been very upsetting for you and on behalf of everyone at Arsenal Football Club I send you our very best wishes.

“It’s sad to hear that you’ve been through what you have, and I can’t even begin to imagine the pain and suffering you have endured.

"I hope you make a full recovery physically and mentally and please keep me updated on your progress.

“I heard you’re a big Arsenal fan which we truly appreciate and thank you for your support.

"As a token of my personal appreciation please find enclosed a shirt which has my name and number on the back.

"On behalf of everyone at Arsenal football club once again I send you the best wishes. Keep supporting the Arsenal and good luck for the future."

Pure class.

Jack has thanked his hero for the gesture.

“I think Kieran is amazing - I had no idea until my mum sent me a picture of him with the top," he said.

"I didn’t believe her at first and then it later arrived with the letter. I’d like to thank him very much for what he did for me.

“I’m a fan of both Arsenal and Tierney. I’ve known who he is since he started playing for Celtic.

“I know where he’s from and some of my mates have met him and said he’s a really nice guy.”