Trent Alexander-Arnold has announced his departure from Liverpool, with a move to Real Madrid now on the horizon.

The England international confirmed on social media that he will be leaving Anfield at the end of this season with Alexander-Arnold ending his 20-year stay at Liverpool as a Premier League champion having won virtually everything for the Reds in his short career.

One defining feature of Alexander-Arnold’s time at Liverpool was his unusual kit number, with the defender wearing 66 after making the leap from the academy to the first team and opting to keep the shirt for his entire spell with his boyhood club.

Yet ahead of Alexander-Arnold joining Madrid, this association with the number will end due to a unique La Liga ruling.

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Football Manager players will be aware of why Alexander-Arnold won’t be permitted to wear number 66 for Madrid, with La Liga rules stating that registered first-team players can’t pick a shirt that exceeds 25, the maximum squad size allowed for a team in the league.

This unique law opens up a lot of interesting quirks for La Liga sides, with FC Barcelona famously banned from not retiring the number 10 shirt for Lionel Messi as it would mean decreasing their first-team squad down to 24 players.

Whilst academy players are permitted to wear numbers exceeding 25, this must change the second their are registered with the first-team, meaning there is no way for Alexander-Arnold to get around this unique law in La Liga.

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Indeed, Alexander-Arnold’s iconic number might not make it to Madrid, but it might take some time before a Liverpool academy player feels brave enough to take on the shirt at Anfield given everything the right-back has done over the years.

Given how tight La Liga rules are on squad numbers, there’s few options available for Alexander-Arnold when it comes to which shirt he could take going into next season, yet the departure of Luka Modric opens up one big prospect for the defender.

The number 10 shirt is expected to be free at the Bernabeu with the Croatian legend set to leave Madrid as one of the club’s greatest-ever players, and whilst 12, 24 and 25 will also be available for Alexander-Arnold, the allure of such a mythical number might be too hard to resist.

With players such as Modric, Luis Figo and Mesut Ozil all wearing the number 10 shirt at Madrid, Alexander-Arnold would back himself to fill in for these greats with the Spanish giants, with the weight of the jersey one that won’t faze the England defender.