One of the priorities for England boss Gareth Southgate is finding a solution to his defensive dilemma, both in terms of shape and personnel.
With the Three Lions setting up with three at the back more often than not, there are spaces up for grabs in the centre of the defence ahead of the World Cup in Qatar later this year.
Southgate is spoiled for choice, but just who are his strongest options? 90min takes a look....
15. James Tarkowski
There's no denying Tarkowski's abilities as a defender, with his no-nonsense style of play and awareness attracting admirers. But he has fallen down the pecking order somewhat thanks to Burnley's struggles in the Premier League.
Not considered the most technically-gifted defender available to Southgate either, he will hoping to reignite his international career with a long-awaited summer move away from Turf Moor.
14. Ezri Konsa
Ezri Konsa has formed a solid partnership with Tyrone Mings in the heart of Aston Villa's defence, with his pace, reading of the game and understated all-around game nicely complementing his partner's style of play.
However, given the plethora of options for Southgate for on the right side, Konsa will recognise there's plenty of other established options ahead of him.
13. Trevoh Chalobah
2021/22 has been Trevoh Chalobah's breakout campaign. The 22-year-old has risen to the challenge of first-team football at Stamford Bridge this season, even chipping in with a few important goals.
Although Chalobah is not in Southgate's plans yet, the departures of Antonio Rudiger and Andreas Christensen will hand him even more playing time at his club next season. Watch this space.
12. Joe Gomez
A few years ago, Joe Gomez being so low on this list would have been unthinkable. Since then though, the Liverpool defender has been cursed by injuries.
Gomez has returned to fitness more recently, and as Southgate is a big fan of his, he remains in contention for a spot in the future. A summer move would help his chances.
11. Max Kilman
From Maidenhead United to being linked with Manchester United – Max Kilman has enjoyed quite the rise.
Performing well in Wolves' back three last season, it is likely only a matter of time before Kilman earns his first cap.
10. Craig Dawson
He may be the wrong side of 30 but Craig Dawson could still have time to break into the England setup.
Even with Kurt Zouma arriving in the summer, Dawson has remained a key cog in the West Ham defence, proving that you are never too old to make your European debut.
9. Tyrone Mings
Mings may not make the most tackles, but he reads the game well and has been key to Villa's strong defensive record in recent seasons.
As a left-footer, he adds a different dimension to the Three Lions backline as well, as he is able to step forward with the ball naturally and find his teammates ahead of him. This allows the defence to explore different avenues in the attack - something which is key for Southgate.
8. Marc Guehi
Marc Guehi's decision to leave Chelsea last summer has proved to be an inspired one.
Just one year on and he has plenty of appearances as Crystal Palace captain and has been handed his first England call-up. You can't say the composed operator does not deserve it either.
7. Eric Dier
Eric Dier further established himself as a key part of Tottenham's defence in 2021/22, putting in assured and confident displays.
As well as being able to read the game well, nipping in to win the ball back, he is also comfortable starting attacks with his excellent passing abilities.
His omission from Southgate's recent squads has got us scratching our heads.
6. Conor Coady
Conor Coady is constantly looking to communicate with those around him, instructing his teammates and ensuring performance levels don't drop.
But as well as being a commanding defender, he has the ability to pick out the forwards with exceptional diagonal passes, getting his side playing on the front foot. A leader with outstanding quality both defensively and when on the ball, Coady will be desperate to secure his spot in the starting lineup.
5. Fikayo Tomori
Speaking of surprise absentees, it is equally, if not more, remarkable that Fikayo Tomori has been overlooked until very recently.
Tomori was a near ever-present for AC Milan as they won the Serie A title this season, and finally got the call-up he deserved in May.
4. Harry Maguire
Is he everyone's favourite defender? No.
Is he perfect? No.
But is he a certain starter should he maintain fitness? Probably.
The Manchester United captain reads the game well, can comfortably play out from the back, and poses a real threat from set pieces too. He loves playing for the Three Lions and Southgate will always keep faith with him despite the negativity surrounding him at club level.
3. Ben White
On current form Ben White is one of the best England centre-back currently available for selection.
Southgate was on the White bandwagon before most of us, selecting the defender in his expanded Euro 2020 squad when most for calling for James Ward-Prowse.
In the months following his call-up White has gone from strength to strength, helping Arsenal record one of the best defensive records in Europe.
2. Kyle Walker
Although he is deployed as a right-back at club level, Kyle Walker has played some of his best international football as a right-side central defender in a back three.
This role suits him well. Perfectly in fact. He has the recovery pace to mop up balls into the channels and the midfield protection of the double pivot allows him to bomb forward at times too.
1. John Stones
After some time in the wilderness a few seasons back, John Stones has returned to the forefront of Pep Guardiola's plans more recently.
In contrast, Stones' England place has never been in serious doubt. He has always been reliable for Southgate and the Three Lions boss likes to reward consistency.