The move came after 170 appearances for Celtic as Tierney also established himself as a regular for the Scottish national team.
And, while his move was a dream come true, Tierney says it was a difficult decision to leave Celtic after nearly 15 years with the Scottish club.
“I would say leaving Celtic was the hardest decision I’d ever had to make and I knew I would always miss Celtic no matter what happens in life,” Tierney said in a Reddit Ask Me Anything, “but the chance to play for Arsenal was a challenge that when I heard of it, I was just looking forward to it.”
Tierney’s time in London has been difficult, though, as the fullback has battled injuries since making the move.
The 22-year-old defender underwent a double hernia operation in May 2019, delaying his Arsenal debut.
However, during that time, he developed a bond with fellow defenders Hector Bellerin and Konstantinos Mavropanos as all three battled back from injury,
“First two people I became friends with were Hector and Dinos as, when I first came in my first sessions, I was walking out with them and they were the first people I really spoke with,” he said.
“We were all injured together at the same time so that’s why they were the first people I really spoke to. They really helped me a lot to settle in.”
Tierney eventually made his long-awaited debut on September 24 before making his Premier League debut one month later.
However, a shoulder injury limited him later in the season, with the defender only making 11 total appearances for Arsenal so far
His debut, though, did give Tierney one memorable moment as he looks to battle back and lock down a consistent place going forward.
“Probably the reception I got from you guys on my debut,” he responded when asked to name his most memorable moment in an Arsenal shirt.
“Making an appearance after injury is always brilliant but the Arsenal fans took me so well with a round of applause at the start as well as when I was substituted so the night of making my debut against Forest was just a great night.”
