Arsenal are understood to be looking for a new left-back this summer with Nacho Monreal set to leave the club.
The Spaniard’s contract ran out on July 1, though his departure is yet to be formally announced.
The Gunners’ pursuit of Tierney suggests he is heading out of the exit door, as they saw an initial £15m bid turned down for the Scot.
Arsenal are understood to have made a fresh bid after Celtic boss Neil Lennon informed them their first offer was well wide of the mark.
“Kieran Tierney has just boarded the BA1491 flight from Glasgow to London Heathrow”
And could the new bid, reportedly still below the Hoops’ asking price of £25m, have done enough to tempt Tierney south of the border?
One Celtic fan claimed on Twitter that the 22-year-old had hopped on a flight to London, insinuating that it could be to secure a move to Arsenal.
“BREAKING NEWS. Kieran Tierney has just boarded the BA1491 flight from Glasgow to London Heathrow. This could be goodbye,” @the_gaz88 wrote.
Many Bhoys fans simply refused to believe the news, demanding photographic evidence.
However, more alert fans claimed that it was to see a specialist as Tierney continues to recover from a long-term hip injury.
Tierney underwent double hernia surgery in May, and is still on a long road back to recovery.
The Scotland international played just a handful of games in 2019 after suffering the injury back in early December last year.
However, Tierney’s fitness problems are not thought to have put Arsenal boss Unai Emery off spending the bulk of his £45m budget this summer on him.
Lennon recently revealed that Celtic had begun their search for a replacement for Tierney, but insisted that he had no plans to let go of the defender.
“Of course [we are looking at replacements]. We had a bid from Arsenal, we respect the bid but we know that’s not anywhere near the valuation we see him at,” he told Sky Sports.
“We are in no position to sell. He’s on a long-term contract, he is an asset and we don’t want to sell.”