Hopes were high for Kieran Tierney when Arsenal were the team to entice him away from his boyhood club Celtic in 2019, but to say the move has been a success would be generous.
The Scotland international has come up with some memorable moments for the Gunners since his switch and established himself as one of the most important players within Mikel Arteta's system when fit. However, 'when' and 'fit' are very much the key words when discussing Tierney's time in North London.
Arteta is a huge fan of Tierney the player, during the Spaniard's first full season at the helm the left-back was arguably Arsenal's most important attacking outlet - though that is a more a damning indictment of the tactical set-up rather than Tierney's prowess.
The former Celtic hero's problem is clear. When Arsenal have needed him most time and time again, Tierney has been side-lined with an injury of some kind. There's a strong chance that recurring theme is the reason behind Arsenal's reported interest in Ajax defender Lisandro Martinez.
The Argentine is a centre-back by trade, but is so comfortable on the ball he can be deployed on the left and slot in seamlessly. Arteta purchased Nuno Tavares 12 months ago to deputise for Tierney, but the Portugal Under-21 international has failed to deliver and is now being touted with a loan exit to Marseille.
Arteta's desperation to bolster his left-back options stems from the fact that Tierney cannot be relied upon to be there when his side needs him. Think back to the Europa League campaign of 2020/21 - Arsenal were forced to use Granit Xhaka as a makeshift left-back in the two-legged semi-final against Villarreal.
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Xhaka gave a penalty away in the first-leg and few could truly be annoyed with the Switzerland international given he was forced to play a role so outside of his comfort zone due to Tierney's absence.
Fast forward to last term and Tierney was ruled out of action for Arsenal's most important run of a season where Champions League qualification was a very real possibility.
From April onwards, Arteta was forced to rotate between using Tavares and Xhaka out of position once again for key games against Brighton, Tottenham and Newcastle as their hopes of a top-four finish capitulated in desperate fashion.
The arrival of Martinez would ensure Arsenal have someone who is not only a more than capable deputy, but someone would who could realistically dislodge Tierney from the starting eleven altogether.
At just 24 years of age, Martinez is reportedly Arsenal's 'defensive priority' signing this summer due to his imposing physical presence and technical prowess, as per The Athletic.
It could also spell the beginning of the end for Tierney, who was already the subject of reports touting him with a switch to Newcastle United earlier this month.