Arsenal are desperate to land a left-back this summer as they look to build on a sturdy first year from Unai Emery.
The Spaniard took over from club legend Arsene Wenger – who was in north London for 22 years before moving on.
And the former Paris St-Germain manager has been tasked with getting the Gunners back into the Champions League – which he failed to do in his debut year.
The Emirates outfit finished fifth in the Premier League and lost to Chelsea in the Europa League final, meaning another year in Europe’s second-rate competition beckons.
But Emery is keen on bolstering his defence – with Celtic full-back Tierney top of the wish list.
The Scotsman is highly-rated north of the border and is adapt at playing across the back-four.
His versatility at Arsenal would be vital, where he could fill in at right-back and centre-back if he is needed to.
An offer of £15m was made but the Hoops rejected it outright – instead demanding a figure of around double that.
And now Tierney’s agent Allan Preston has revealed Tierney will likely leave if Celtic receive their desired fee.
“It is all down to Celtic, if they get a price that they believe is the correct value for Kieran Tierney he could possibly be on his way,” Preston told BBC Sportsound.
“No one has hit that price yet. I know Kieran really well, I had some food with him the other day, he is such an unassuming young man.
“He is wealthy at the moment but he doesn’t possess a watch, he isn’t into material things like this.
“He still hangs about his pals from when he was a youngster, he sponsors his local pub team where his pals play and he’s not into his designer gear or anything like that.
“As the guys say he loves Celtic, he absolutely loves Celtic. Will there be a time for Kieran Tierney to go?
“I think that there will be, if it’s just now it will be up to the clubs involved.
“Arsenal, Napoli or whoever to then put the money on the table and make Celtic think about this.
“If he is on his way he’s on his way. If there is a time for Kieran to go it will be up to Celtic, Peter Lawwell and the board.
“They have signed a left-back (Boli Bolingoli-Mbombo) but they do need one because Izaguirre is away. The ball is firmly in Celtic’s court.”