It's quite damning in itself that signing yet another centre-back should even be a consideration for Manchester United this summer, but here we are.
Despite spending an ungodly amount of money on defenders in recent years, United continue to have a porous backline and have conceded more than any other team in the top four this season and the joint-most in the top six.
As a result, even more reinforcements may be needed there in the summer, which only adds to a United to-do list that also includes the vital acquisition of a quality defensive-midfielder.
Raphael Varane has played well after adapting to the more physically imposing Premier League but his injury record remains a concern. Captain Harry Maguire has been in a rut of form and repeatedly costs his side goals. Victor Lindelof has actually looked bright when he's played but has a quality ceiling. For Eric Bailly and Phil Jones, the time of them being considering reliable first-teamers has long passed.
The likes of Teden Mengi and Di'Shon Bernard offer intriguing options to bolster the squad from the academy but it would be unfair to expect them to inject the quality United need if they were called up to the first-team.
No, another signing in the summer is the best solution. But that costs money, as United well know. And considering they'll need an awful lot of it if they hope to sign just one let alone both of Declan Rice and Erling Haaland, then there might not be much spare to spend on the defence.
It's handy, then, that Chelsea's Antonio Rudiger could be available on a free.
The German has been locked in contract talks with the Blues for months now with no sign of a solution being found, which increases the chances of him leaving for nothing when his contract expires in the summer.
Our sister publication the Daily Mirror reports that, along with Real Madrid and Paris Saint-Germain, United are keen to sign Rudiger and it could be an interesting signing.
His wages and any signing-on fee would, of course, still prove expensive but such a quality defender on a free transfer is certainly a tantalising prospect.
Rudiger has been a colossus for Chelsea since Thomas Tuchel was hired, making his exclusion by previous manager Frank Lampard even more perplexing.
The 28-year-old was paramount in the London club's Champions League triumph last season and has remained an ever-present in the side this term. Losing him would come as a massive blow to Chelsea.
United would have some stiff competition for his signature, with Madrid looking the favourites, but a defender so capable of organising the backline and sweeping up others' mistakes sounds exactly like what they need.
There's every reason why Ralf Rangnick should be keen.
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