Arsenal are continuing to test Celtic’s resolve this summer by increasing their offer for left-back Kieran Tierney to £25million.

The Gunners saw an initial £15million bid promptly rejected by the Scottish champions three weeks ago but have returned with a much-improved fee.

A hernia issue restricted Tierney to just 21 league appearances for Celtic last season, but the money Arsenal are willing to offer would make him the most expensive player in Scottish football history.

Moussa Dembele currently holds that title after Lyon paid £19.7million for his services last summer, but the most recent offer for Tierney must have turned heads at Parkhead.

The Hoops are under no pressure to sell, with the 22-year-old contracted until 2023, and eight players have already left during the current window including Mikael Lustig and Dedryck Boyata.

Tierney shot through the Celtic ranks before winning four Scottish Premierships, two Scottish Cups and two League Cups with the first team.

Will Kieran Tierney be a Celtic player by the end of the transfer window?