Kieran Tierney claims he was "down the park with friends" when he got the call to seal a transfer to Arsenal, with a frantic dash to the airport undertaken on deadline day.
The 22-year-old moved to the Emirates from Celtic for a £25 million ($30m) fee on Thursday afternoon, signing a five-year contract with the north London club.
The Gunners had been chasing the Scottish defender's signature throughout the summer window, with Unai Emery aiming to shore his team up at the back ahead of the 2019-20 season.
The Spanish boss got his man in the end, with Tierney becoming Arsenal's fourth permanent signing of 2019.
The ex-Celtic man was forced to endure a hectic 24-hours of travelling to finalise the transfer, however, having been summoned to the Emirates while enjoying a training session with his friends.
Tierney told Arsenal's official website: "Well I got told at seven o'clock last night that I had to be at the airport in an hour, so I had to go quickly. I was actually down the park with my friends training.
"They play with their local team so I was down watching them and I got a phone call that I needed to go.
"I got to the airport and the flight was delayed two-and-a-half hours, with another hour's drive for a hotel and I probably got zero sleep, so I was back up at half five today."
The Scotland international will now compete with Sead Kolasinac for the left-back spot in Emery's starting XI and he has already been backed to succeed in new surroundings by Celtic legend Davie Hay, who feels he will be a "sensation" for the Gunners.
Tierney followed previous summer acquisitions Nicolas Pepe, William Saliba and Gabriel Martinelli to Arsenal, while David Luiz was also brought in from Chelsea for £8 million ($10m) on deadline day.
Arsenal open their latest Premier League season away at Newcastle on Sunday, but Tierney is unavailable as he continues to recover from double-hernia surgery.
He went on to give an update on his rehabilitation progress, while also revealing it was a "hard decision" for him to leave Celtic at this stage of his career.
"I'm just getting back fit now, I'm just getting back involved with a ball and back running," said Tierney. "So hopefully it's not going to be too long.
"It was the hardest decision in my whole life that I've had to make. I had to speak to my family and my close friends and my agent as well because it's a hard decision to leave a club that you love so much.
"People need to know that as well. I feel Arsenal is a massive club and it's a great opportunity for me as well. I'm delighted to be here."