The case of William Saliba is probably one of the most curious in Arsenal's transfer history.
The Frenchman was signed in the summer of 2019 before being immediately loaned back out to St. Etienne for the season - nothing particularly strange there, especially given that Laurent Koscielny was fully expected to see out one more year at the Emirates at the time.
However, the weirdness began the summer after. Having missed much of his spell back with Les Verts due to injury and the early termination of that Ligue 1 season due to Covid-19, Saliba was left out of Mikel Arteta's squad for the 2020/21 campaign and forced to play under-23s football before joining Nice for the second half of that season.
Another loan spell at Marseille this year means that nearly three years on from being signed, the 20-year-old is still yet to make his competitive senior Gunners debut. That could be about to change very soon though.
football.london understands that Arsenal intend to welcome Saliba back into their squad this summer.
With Calum Chambers having left to join Aston Villa and Pablo Mari on loan at Udinese as a consequence of his currently out of first team plans, this would seem to indicate that the Frenchman will be returning to North London to be part of Arteta's squad.
Given that Saliba has just been nominated for Marseille's player of the month award for January, this is undoubtedly positive news. However, the 20-year-old has a battle on his hand to secure regular game time regardless of his form in Ligue 1.
The established first choice central defensive partnership at the Emirates is Ben White and Gabriel, who have played a part in 12 clean sheets this season.
Rob Holding meanwhile has gained specific praise from Arteta due to his professionalism in the face of limited minutes for much of this season.
"His attitude, his commitment to the team whether he plays every week or plays one minute, it's incredibly good," the Spaniard said. "He's a really good influence for the rest."
With this in mind it seems possible that Saliba may be being considered as a solution to another area of the squad where Arsenal have had problems.
Since his arrival from Bologna on transfer deadline in the summer, Takehiro Tomiyasu has had the starting right back spot pretty much nailed on.
The Japanese international's defensive solidity has played a huge part in White's impressive form, while his two-footedness has been an invaluable asset as the Gunners looks to play out from the back and higher up the pitch.
However, without a direct tactical replacement for him Arsenal have struggled at times.
Cedric has largely done well when called upon, and was impressive in last week's 1-0 win against Wolves, however, the Portuguese international is more of traditional attacking full back than the inverted type that Tomiyasu is.
As a result, it has been suggested that Edu may be on the hunt for a right back this summer to provide more similar cover to the Japan defender.
This though could be complicated. Having been linked to Atletico Madrid in January, Cedric is now thought to be fully focused on helping Arsenal qualify for next season's Champions League.
It remains to be seen whether that will change in the summer, but if the 30-year-old wants to stay in North London, then signing another right back on top him and Tomiyasu may not be feasible.
Saliba though could be a solution for this.
The Frenchman has played right back during his time with Marseille. When asked to perform this role by Jorge Sampaoli at the Stade Velodrome, his responsibility has not been so much to get forward and support the attack, but rather to provide defensive cover and passing options in build up play, just as Tomiyasu does for Arsenal.
The Japanese international is back in training after missing nearly a month of football due to a calf injury that was aggravated in last month's Carabao Cup semi final second leg defeat to Liverpool, and could potentially be in contention for selection against Brentford on Saturday.
But having seen how his team struggles without the Japanese international, the return of Saliba could provide the kind of back up Mikel Arteta is looking for, saving him the trouble of having to delve in to the transfer market to find some.
