In recent years, Celtic have developed something of a reputation for developing promising young talents before selling them on for big transfer fees – be those players that the Bhoys have grown within in their own academy, or ones signed for a minimal cost from lesser-known clubs.

Recent examples of this would be Kieran Tierney – who joined Arsenal in a £25m move back in 2019 – Moussa Dembele – who joined Olympique Lyonnais in a £19.7m deal back in 2018 – and Virgil van Dijk – who joined Southampton in a £13m move back in 2015.

Indeed, of these three players, Van Dijk was the only one who cost the Hoops an outlay – £2.6m, to be exact – as Tierney was a product of the Celtic youth system, while Dembele arrived from Fulham on a free transfer.

However, while there are plenty of examples of Celtic getting it right in the transfer market, there are also occasions in which they got things horribly wrong – none more so than with Andy Robertson.

Released from Celtic, now worth £58.5m

Having joined Celtic academy all the way back in 2003, the Hoops ultimately decided against offering the left-back scholarship terms in 2009, with Roberston himself suggesting that the club’s reasoning for doing so was due to his diminutive stature.

Speaking in 2013, the defender said: “I was let go by Celtic at U15 level for being too small. That was the reason they gave me anyway. Being told that by Celtic made me determined to succeed. It was hard to take, nobody wants to get told they are not at that club any more, and my confidence took a hit.”

And, after stepping down the leagues to join Queen’s Park, Robertson quickly worked his way back towards the top of the footballing pyramid, joining Dundee United on a free transfer in 2013, before making a switch to Premier League side Hull City just a year later in a £3.24m deal.

Then, following three impressive seasons with the Tigers, the 27-year-old who Fabio Aurelio dubbed a “complete player” took the final step in his remarkable comeback from being released by Celtic, joining Liverpool in an £8m deal in 2017 – a club with whom the £160k-per-week defender has gone on to win practically everything there is to be won at club level, including the Champions League, Premier League, FIFA Club World Cup, the UEFA Supercup and the Carabao Cup.

Indeed, Kenny Dalglish took the time to praise the Scotland international’s astonishing comeback story, stating: “For Andy to be where he was just seven years ago – when he was let go by Celtic – to where he is now, is a classic example to any young footballer that you should never give up and never stop believing.”

However, not only is there a lesson for aspiring young footballers to learn from the Liverpool star’s story, but there is also one for Celtic.

Indeed, the club’s short-sightedness on a player who Jurgen Klopp dubbed a “monster” has cost them big time in the transfer market, as Robertson is currently valued at a whopping £58.5m by Tranfermarkt – something which proves Celtic had a nightmare on their one-time left-back.

In other news: Ange must avoid disaster on “big player”, he may be Celtic’s next £49.5m-rated talent