The Gunners are thought to have made a fresh offer for the Scotland international as Arsenal boss Unai Emery looks to add the 22-year-old to his squad.
The north London side are rumoured to have made a £25m bid for the Celtic full-back but the deal includes a lot of add ons.
Arsenal have reportedly failed with bids of £15m and £18m for the highly-rated left-back in the summer transfer window so far.
Sky Sports News reporter Solhekol has now revealed that Arsenal will need to offer more cash up front in their proposed £25m deal to convince Celtic to sell.
Solhekol wrote on Twitter: “Arsenal £25m offer for Celtic left back Kieran Tierney includes too many add ons dependent on Arsenal qualifying for Champions League. Celtic not convinced they’re realistic. Want more cash up front.”
Tierney has won four Scottish Premier League titles, two Scottish Cups and two Scottish League Cups since breaking into the Celtic team as a teenager.
The Celtic defender has also won the Scottish Young Player of the Year award in the last three seasons at the Parkhead side.
Tierney has scored eight times in 170 games in all competitions over the past five seasons to get plenty of experience under his belt.
Arsenal have only signed Brazilian teenager Gabriel Martinelli in £1.6m deal from South American side Ituano so far this summer.
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