Without batting an eyelid, the Welsh club felt able to turn the offer down.
They apparently value McBurnie at closer to £20m.
If Premier League newcomers Sheffield United, or anyone else, are prepared to stump up that fee, then McBurnie would become the most expensive Scottish footballer in history, eclipsing the £15m West Bromwich Albion paid RB Leipzig for his international team-mate Oliver Burke.
McBurnie is clearly a more than proficient goalscorer at Championship level as his tally of 22 in 42 appearances for Swansea in the second tier of English football last season indicated. But the 23-year-old failed to find the target in 16 outings for the Swans when they were in the Premier League and has yet to get off the mark on the international stage in his seven appearances so far for Scotland.
When a club are prepared to shell out £15m for a player still unproven at the highest level, it certainly vindicates Celtic’s valuation of Kieran Tierney at £25m.
The Scottish champions are absolutely not prepared to sell their left-back and prize asset to Arsenal for a penny less during the current transfer window – and quite rightly so.