During the summer, the Scottish youngster underwent a double hernia operation and as per reports, the player still needs a few weeks more to fully recover.
This means that Kieran Tierney is likely to miss a number of games for the new season but still the Gunners chose to pay around 25 million pounds for him.
The official statement regarding his signing read: “Scottish international Kieran Tierney has joined us from Celtic on a long-term deal.
“The 22-year-old was born in the Isle of Man and had been with his boyhood club since the age of seven. He made 170 appearances for Celtic and has played 12 times for Scotland.
“The defender completed a medical at London Colney on Thursday and will immediately join-up with his new teammates. He will wear the No 3 shirt.”
And speaking about his newest defender, Unai Emery said: “We’re delighted Kieran is joining us. He’s a very talented player who will continue to improve. He increases our options defensively and I look forward to him joining our group.”
Arsenal have reportedly handed Kieran Tierney a five-year deal at the club but according to his former teammate Scott Brown, the young left-back could very well end up playing for a big European powerhouse like Barcelona or PSG.
“You don’t know what could happen,” he told the Herald(as reported). “He could have a fantastic couple of seasons and end up at Barcelona or PSG or wherever.”
“There are pictures on the wall all over the club of players who have left and everyone would wish them all the best,” he said. “They can come back as well, that’s what this cub is all about.
“I see Ajax bringing players through and selling them on – and they have a party for them leaving. We try and criticise. It’s a different level.
“We wish him all the best. We just concentrate on now and Boli (Bolingoli, new left-back) has to push on and try to get to the levels that Kieran did.”
Arsenal have seen a number of their top talents head to Barcelona in the past hence many people will not be ready to put money against Kieran Tierney heading in the same direction.