When Kieran Tierney left Parkhead behind it was a sucker punch to their ambitions.
Yet again, a Celtic player was leaving for the Premier League, and once more, it was one of their star men.
The Hoops have been no strangers to seeing their most valuable assets leave. From Victor Wanyama to Moussa Dembele and Virgil van Dijk, a plethora of their top players have left in search of a top-five league.
Tierney is the most recent example, swapping Glasgow for London, joining Arsenal for £25m – a record sale for an SPFL player.
He has taken to the English top-flight like a duck to water, scoring and assisting in a rampaging display against West Brom last weekend. It was the type of performance that will have Celtic supporters craving a return.
However, for the time being, they have to settle for Greg Taylor and Diego Laxalt at left-back, two players who seldom replicate what Tierney can offer down the left flank.
Fortunately, they could be on the verge of finally landing the Scot’s true replacement. That happens to be Charlton winger Alfie Doughty.
Capable of playing as a left-back or further forward in attack, he has been continuously linked with the Bhoys since last summer. Though, in order to sign him, they will now have to fend off interest from Rangers.
Doughty is out of contract in the summer and thus, can be signed on a pre-contract agreement for a fee of absolutely nothing.
But why is he similar to Tierney? Well, a glowing review from The Athletic’s Nick Miller tells all: “Pace is the first thing you notice about Doughty. Remarkable pace. Relentless pace. The sort of pace that makes defenders cower and do very silly things indeed,” he wrote.
That is a frightening assessment, one that could well describe their former left-back. He demonstrates sheer speed on a regular basis, and like Doughty, makes defenders do rather strange and peculiar things.
Tierney showed that vs West Brom, taking Darnell Furlong for a walk before finding the back of the net in emphatic style.
Aged just 21, Doughty is the future and could well inspire Celtic to greater things.