Kieran Tierney is in London undergoing a medical with Arsenal ahead of a move from Celtic.
Arsenal agreed a fee with Celtic on Wednesday for the Scotland international left-back.
Arsenal's initial £15m bid for Tierney was rejected in June, as was a second £25m offer, as it contained too many add-ons and was dependent on the Gunners qualifying for the Champions League.
The 22-year-old, who has won five Scottish Premiership titles, made 40 appearances in all competitions for the Hoops during the 2018/19 campaign.
If Arsenal are able to complete the deal for Tierney, he would be Unai Emery's fifth signing of the summer window.
Tierney signing 'a statement of intent'
Former Arsenal striker Charlie Nicholas thinks Kieran Tierney's arrival at the Emirates would be a statement of intent by the Gunners.
"As a Celtic and Arsenal fan, I'm happy Arsenal have identified they need a stronger left back," the Scot told Sky Sports News. "Tierney has improved a lot, he'd be better than what Arsenal currently have. I think it's a high price, he's been a treble-treble winner and it's been an awkward situation for him, but I think the time is right for him to move on.
"Celtic fans might ask why he doesn't stay for nine in a row. That's not guaranteed, neither is 10. Going to a big club like Arsenal, in the Premier League, you can't guarantee trophies, but they are signing a very good left back who can get better. And I think they needed to make a statement of intent defensively because they look very exciting going forward."
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It's Transfer Deadline Day for the Premier League and Championship on Thursday - and Sky Sports will be bringing you all the latest news on who your club is signing.
Start your day with Deadline Day Breakfast (6am) ahead of a special Good Morning Transfers show (9am), with Deadline Day - The Countdown (4pm) taking you to the 5pm deadline.
The Transfer Show - Deadline Day at 6pm will analyse the big moves before Deadline Day at Ten rounds up all the transfer headlines.