Heading into the September international window, you'd be forgiven if you thought one of Gareth Southgate's biggest problems was that he had too much depth available to him at right back. Trent Alexander-Arnold was left out of the Nations League squad due to poor form with Liverpool and left back Ben Chilwell didn't play a minute while working his way back to fitness for Chelsea since his ACL injury last season with right back Kieran Trippier pushed out to the left. Fast forward less than a month and things have changed for the Three Lions. Reece James and Kyle Walker will both likely miss the World Cup due to their respective injuries and the knock on effects have now created issues at both fullback positions and at center back.
In Southgate's preferred 3-4-3, Walker has become the preferred center back on the right side with James as the right wing-back, but James is also a backup option in central defense for Walker, a role which become especially important with center back John Stones also injured for Manchester City. But with both of his right sided hybrid options out, Southgate has limited options where he was supposed to have more players than he could pick.
With Kalvin Phillips also sidelined in midfield, the personnel crunch is not limited to the right flank and it means that the midfield position is also too thin to consistently transition to a 4-3-3 formation to cover for the lack of Walker, unless Southgate can trust Conor Gallagher and Ruben Loftus-Cheek, neither of whom are earning consistent playing time at Chelsea ahead of Qatar. Assuming that England sticks to a base 3-4-3, it's likely that Keiran Trippier could be the starter at right wing back after Southgate said that his all around game is ahead of Alexander-Arnold back in September.
There's certainly an argument for that, as Trippier has been a lynchpin in Newcastle's defense with the Magpies enjoying a good start to the season but due to the glut of right backs, Trippier has been one of the top options at left wing-back as well, so starting him on the right does hurt Southgate's team depth. One way around this has been to use a more attacking player like Bukayo Saka at left wing-back when Trippier moves to the right, but that has its own limitations as it would hurt Southgate's tactical flexibility and prevent the team from shifting to a back four when necessary.
Luckily in Alexander-Arnold, Southgate will still have a top option at right back, even if he is one that has had a less impressive career with England than Liverpool. But Alexander-Arnold is himself just returning from injuries and both him and Trippier have dealt with multiple muscular injuries over the past few years. So even if there's still enough cover, for now, the situation has gone from an overabundance of riches to one of scarcity.
The impact on central defense is where the most strain will be felt as Walker has been ever present as Southgate's top choice there. And now, not only will James not be an option, but Stones also hasn't appeared for Manchester City since September 17th against Wolves. Pep Guardiola has been coy about setting a return time for Stones which puts Southgate down to bare bones at center back.
His usual depth options are Conor Coady -- who prefers operating centrally in a back three -- and Marc Guehi -- who plays on the left at Crystal Palace. It would make the most sense for that to create an opportunity for James Tarkowski who has helped Frank Lampard improve the Everton defense or Fikayo Tomori who has been strong for AC Milan despite struggling a bit recently.
Both center backs could do the job defensively, but they don't offer nearly as much as James or Walker in possession or when it comes to pace. And in a group stage involving the USMNT, Iran and Wales England's back line should both see lots of possession and also have to deal with the likes of Tim Weah and Christian Pulisic looking to counterattack them at speed. Whatever solution England ends up going with, In these situations Southgate will need to rely on Declan Rice in midfield to keep things ahead of him in the center of the the pitch and slow down counters before they can victimize the back line. If England can control possession, the team has a good enough attack that it may not matter, but they're susceptible to being picked apart by counterattacking teams in ways they wouldn't be with a clean bill of health.
Moving to the left side of the pitch, with Trippier likely no longer able to shift over, things are in flux there as well. One of Southgates' preferred option, Luke Shaw, is back in a starting role for Manchester United but he has a tenuous grasp on the job and is probably only a bad performance away from Tyrell Malacia taking back the starting role at Old Trafford leaving England with limited options on the flank. Chilwell is back to playing regularly for Chelsea and can offer more going forward than Shaw which could help keep Saka in the front three instead of seeing him shift back as a left wing-back.
In terms of the back end of Southgate's squad, the biggest winner could be Crystal Palace's Tyrik Mitchell. He has been able to lockdown top attackers in the Premier League and could be a late game sub for Southgate to containing attacks who are throwing everything forward and with James and Walker sidelined he now has a chance at grabbing one of the last seats on the plane.
While the Three Lions losing their tip fullbacks is quite a blow it could help ensure that Southgate isn't drawn into a conservative gameplan at the World Cup. With his preferred formation having weaknesses in the group stage, England could shift to a three man midfield if Chelsea provides enough options to make it happen. As the team has enough talent to go directly at most teams in the world, leaning into that instead of relying on the defense could end in an improbable run to the World Cup Final.