Former Republic of Ireland goalkeeper Packie Bonner has questioned whether or not Arsenal are a big enough club for Celtic defender Kieran Tierney.
The Premier League side reportedly had a bid of £15m rejected for the Scottish left-back over the weekend and are expected to come back with increased offer for his services as they look to find a long-term option for the left side of their defence.
But Bonner says he is unsure whether or not an organisation of Arsenal's stature is a big enough club for Tierney after the Gunners missed out on Champions League football for the third season in a row.
Speaking to the BBC, Bonner - who made 642 appearances for Celtic during a playing career which saw him represent Ireland at two World Cups - said that Tierney's value would be doubled if he played for an English club instead of in Scotland.
"If Kieran was playing in England, he'd probably be worth about £50m. But because it's Scotland, I would think £25m would be a price you'd start talking about, with add-ons.
"He's got the ability to go into a club like Arsenal. Whether Arsenal is a big enough club for Kieran Tierney, that's the question.
"If you were picking out a player in British football at the moment that can play left-back, himself and [Liverpool's Scotland captain] Andy Robertson are the best two in Britain, if not Europe."
Arsenal are expected to return with a bid of around £25m for Kieran Tierney this week, though it still remains to be seen whether or not that will be enough to tempt Celtic into parting with the 22-year-old.
Tierney's current deal at Cetlic Park runs until 2023 and could yet be convinced to stay with his boyhood club.