The 22-year-old was heavily linked with a move to The Emirates throughout the summer transfer window but the switch only came to fruition on Thursday last week.
Tierney will now be hoping to hold down a regular spot in the Arsenal team under Unai Emery as he looks to try and establish himself as a first-team regular at The Emirates.
And former Gunners star Hartson feels that the north London side have made an excellent signing by bringing in the defender.
Writing in a tweet posted shortly after the transfer, Hartson said: “Arsenal are getting a fine player, a wonderfully grounded boy, been brought up in humble surroundings, I can only wish Kieran Tierney a great career.
“Been brilliant for Celtic. Good luck mate 👍🏻.”
The left-back will be hoping to make his debut for Arsenal when the Gunners take on Burnley in the early kick-off on Saturday at The Emirates.
Arsenal got their new Premier League season off to a solid start last weekend when they sealed a 1-0 win over Newcastle United thanks to Pierre-Emerick Aubameyang’s goal in the second half.
The north London side will have their sights firmly set on securing their spot in the top four this season and a return to the Champions League.
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