The Scotland international move to the Emirates Stadium last summer in a deal worth around £25m after months of speculation.
Tierney has played just 11 times this season due to separate hip and shoulder injuries and Tierney admits it wasn’t the easiest decision to move to Arsenal.
"I had sleepless nights. It was a hard decision," said Tierney (via the Metro).
"I knew how big Arsenal were. They are a massive club in a massive league. I'm coming down here and I’m playing in training against (Nicolas) Pepe, (Mesut) Ozil, (Alexandre) Lacazette and (Pierre-Emerick) Aubameyang every day. You’re playing against the world’s best players".