Leeds United currently boast two first-team goalkeepers: Illan Meslier and Kiko Casilla.
The 21-year-old Frenchman is indisputably the Whites' No. 1, playing 35 of last season's 38 Premier League fixtures.
Casilla stepped in during Meslier's illness for the 1-0 defeat to Brighton & Hove Albion in January, before playing in Leeds' final two league games in front of spectators versus Southampton and West Bromwich Albion.
Undoubtedly one of the game's most isolated positions, the life of a stand-in stopper can be a lonesome and fruitless one.
Casilla travelled with the squad for almost every Premier League fixture this season, but was given just 270 minutes on the pitch.
With two years remaining on his contract at Elland Road, and Illan Meslier getting better with each week, Casilla could live out his existence at Leeds United whilst not seeing a great deal more time between the posts.
Manchester United are on the verge of completing the signing of Aston Villa 'keeper Tom Heaton this summer, which would see him become the club's third-choice behind Dean Henderson and David de Gea.
The likelihood of Heaton featuring regularly at Old Trafford is close to nil, but at 35 years old and an expiring contract at Villa Park, it is a role more and more goalkeepers are willing to take.
Heaton will replace 38-year-old Lee Grant, who has been Man United's third-choice stopper for three years.
In that period he has played twice in all competitions, and this past season featured in no minutes for Ole Gunnar Solskjaer's side.
Casilla's future promises to be more of the same.
It is well-documented that the veteran Spaniard is one of the better-paid players at Elland Road, which presents a two-pronged problem.
A goalkeeper who is not contributing on the pitch being a high-earner is a drain on resources, while trying to offload the 34-year-old will prove increasingly difficult the longer he spends on the sidelines, especially as interested teams are not obliged to match his Elland Road wage.
If Leeds were able to sell Casilla this summer, they could reinvest those resources into bringing in a younger second choice who will run Meslier closer for the No. 1 spot.
In the present circumstances, Meslier knows he is a shoe-in for the starting berth. Whereas, if a more capable deputy was targeted this summer, it is conceivable Meslier would be pushed to improve, in order to retain his shirt - a positive externality of moving the Spaniard on.
