It is telling that Sunderland head into a crucial Premier League game sweating on the fitness of John O’Shea.
That is no slight on the Irishman, as dependable as ever and a fine servant. In an impressive performance at Everton last month, he kept Romelu Lukaku quiet, the Belgian only finding joy when he pulled onto the Black Cats’ other defenders.
Nevertheless, it says much that this has turned into yet another campaign when a long-term successor to the 35-year-old has not emerged.
Sunderland enter the final 10 games of the season still searching for their best defensive partnership.
Papy Djilobodji and Lamine Kone for a time looked to be building something, but the former still has much to iron out and has not featured since lashing out at West Brom’s Darren Fletcher.
Kone has not approached the heights of last season, even if he remains the best centre-half at the club and one of the first names on the teamsheet.
On-loan Jason Denayer has speed, energy, and seems to read the game well, but he is still developing a real stature and will almost certainly not be at the club next season.
So much of building a successful team is about partnerships, building trust among players.
At the heart of defence, arguably the most important department of all, Sunderland have not been able to build continuity.
Part of that is due to injury, and part of it due the need to play O’Shea because of his experience and leadership. He and Djilobodji have struggled when they have played together and that has caused problems.
Younes Kaboul’s absence to tomorrow’s hosts, Watford, for £3million is still keenly felt.
Sunderland were left in an impossible situation once Kaboul was left wanting to head south for personal reasons, even though his form in the second half of last season surely warranted a greater fee.
The biggest issue was not finding a way to replace his leadership and communication skills.
Djilobodji was evidently the kind of player who needed someone like Kaboul to play alongside him, rather than take his role.
The off-the-field saga with Kone was well documented, but part of his slightly diminished form is also surely down to losing such a supreme organiser and communicator alongside him.
The caveat to this was his indifferent form in the first half of last season, and it is certainly true that he has not been such a rock at Vicarage Road this season.
He has, however, further dispelled any doubts about his body by completing the vast majority of Premier League games this season.
Kaboul represented the perfect successor to O’Shea, able to lead like the former Manchester United man but also with the speed to succeed in the Premier League.
His departure last summer was far from the most high-profile event for Sunderland, but it was nevertheless one of the more signficant.
David Moyes now has a big selection call to make at the back.
Does he stick with Kone and O’Shea, who have been relatively stable if not entirely convincing? Does he sacrifice O’Shea’s experience for greater speed?
Or go with three as an added buffer?
Whatever he decides, most of what he is looking for was provided by Kaboul.
His departure was a decision with no real alternative, but the failure to replace him still harms the team’s prospects.