Gareth Southgate's wing back options with England set for 3-4-3: Luke Shaw and Kieran Trippier are injury doubts while Kyle Walker is set to move inside... so, could it be time to drop star boy Bukayo Saka back on the left?

England are expected to switch from their 4-2-3-1 formation to a 3-4-3 system when they take on Switzerland in Saturday's Euro 2024 quarter-final.

The planned move has been motivated in part by a one-match suspension handed to centre back Marc Guehi, with manager Gareth Southgate keen to provide additional cover at the heart of his defence.

However, the shape change also has the potential to make England more threatening going forward, by giving extra freedom to the players in midfield, including the two wing backs.

The big question is, though, who will Southgate opt to play out wide against a Swiss side that are also expected to line-up with three at the back?

Mail Sport has taken a look at the candidates, starting with a player who has not made a competitive appearance for club or country since February.

Luke Shaw (left wing back)

Manchester United star Luke Shaw is the only specialist left back or left wing back in England's current squad.

If fit, he would unquestionably be the top choice to start as England's No 3 - just as he did in the final of Euro 2020, when he scored against Italy after less than two minutes. However, Shaw is not fully fit. His last proper appearance was 20 weeks ago when he suffered a hamstring injury while playing for United.

Shaw has at least spent the last week training with his England team-mates, having started the summer on a personal programme. It remains to be seen whether he has done enough to convince Southgate that he is ready to play.

When fit, Shaw's dynamism is one of his top qualities. His pace allows him to race up and down the flank and affect the game at both ends.

However, while more defensively solid than some of England's other wing back candidates, Shaw is not the most prolific in terms of his attacking output. He has so far produced 17 assists and just three goals over his 251-game Premier League career. That averages out as one goal contribution every 12.55 matches.

Trent Alexander-Arnold (right wing back)

Liverpool ace Trent Alexander-Arnold is much more productive going forward.

The 25-year-old - who started England's first two group games in central midfield - looks like a strong choice to switch to right wing back.

Alexander-Arnold's crossing and passing ability is among the best in Europe and he has delivered 15 goals and 58 assists in 226 Premier League appearances for Liverpool. That is a goal or assist every 3.10 matches.

The main - or perhaps only - argument against Alexander-Arnold is that he is not the strongest option defensively.

However, any fears could largely be mitigated by Southgate deploying Kyle Walker as his right-sided centre back.

Kyle Walker (right wing back)

Manchester City captain Kyle Walker has started England's first four Euros games at right back. Therefore, many would see his most natural position in a 3-4-3 system as right wing back.

However, as suggested above, Southgate is likely to want Walker to play as part of his back three.

Walker played as a central defender five times at the 2018 World Cup and was also deployed in that role against Germany and Italy at Euro 2020.

It is likely that Walker will again move inside on Saturday but one could make an argument for him to start out wide, considering how many options Southgate has at centre back - namely John Stones, Ezri Konsa, Lewis Dunk and Joe Gomez.

Kieran Trippier (left or right wing back) 

Newcastle United captain Kieran Trippier is a player suited better than most to a formation that utilises wing backs.

Trippier was England's first choice right wing back at the 2018 World Cup and it was also from this position that he assisted Shaw in the final of Euro 2020.

Like Alexander-Arnold, Trippier is capable of delivering wicked crosses. He also has an excellent understanding with captain Harry Kane, having played alongside him at Tottenham for many years.

Trippier limped out of England's 2-1 win over Slovakia last week and is therefore a slight fitness doubt for Saturday.

If he is fit, he could be an option to fill in at left wing back, having started the last four games at left back. However, he would be much more comfortable and effective on the right.

Trippier's Premier League career to date has seen him score six goals and set up another 35 in 179 appearances - a rate of 4.37 games per goal contribution.

Bukayo Saka (left wing back) 

The thing about 3-4-3 is that it can be a very fluid system and how it operates depends largely on the personnel.

So, if Southgate was feeling bold - however unlikely that may sound - Arsenal forward Bukayo Saka could be the man to play at left wing back.

Saka has been one of the Premier League's best attackers over the past four seasons, scoring 54 goals and providing 30 assists in 143 outings for the Gunners.

Those remarkable figures - which work out as a goal or assist every 1.70 games - have not been recorded while playing as a wing back.

However, Saka did play this role earlier in his club career. He also played as a left wing back for England in November 2021 when Southgate was feeling bold, albeit against San Marino. England won that game 10-0 with Saka scoring the 10th, while Alexander-Arnold made three assists.

Eberechi Eze (left or right wing back)

If the idea of Southgate playing Saka as a wing back against Switzerland was not bold enough then the England boss could instead - or as well - opt to deploy Eberechi Eze in that role.

It might seem outlandish to put Crystal Palace's tricky forward into a somewhat defensive area of the pitch. However, that is where he ended Saturday's game against Slovakia.

England were left with a seemingly unbalance side after Southgate had thrown on various attacking players in a desperate bid to draw level.

But Eze looked okay at left wing back. As he is naturally right-footed, one can only assume he would be at least equally as comfortable on the opposite side.

Though certainly risky, starting Eze as a wing back would at least give England more creativity from deep positions, something that has been badly missed throughout this tournament so far.

The 26-year-old former Queens Park Rangers star has scored 26 goals and provided 38 assists in 112 Premier League games since joining Palace in 2020 - at a rate of one goal contribution every 1.75 matches.