It’s a formation associated with misery in recent Pompey memory.
But Kenny Jackett is mulling over a return to a wing-back formation as the Blues go to AFC Wimbledon.
Jackett experimented with a 3-5-2 formation in the second half of Tuesday’s Checkatrade Trophy win at Crawley.
In his time as Pompey manager it’s not been an approach conducive to producing results, however.
Wing-backs were rolled out for the visit of Gillingham in March – an afternoon which saw the away side grab a first win at Fratton Park in 106 years of trying.
The game started brightly enough for Jackett’s side as Jamal Lowe gave his team the lead.
But former loanee Conor Wilkinson levelled after the restart and then two goals from Lee Martin ensured victory for the Gills.
It was similar story when Rotherham came to PO4 in September of last season and picked up a 1-0 success.
Jon Taylor got the only goal of the game in the 36th minute, with Jackett ditching the wing-back system at the interval.
The win for the Millers was their first victory in 26 away trips on a day to forget for Pompey.
Before Jackett became manager, Paul Cook introduced wing-backs for the trip to Stevenage as his side vied for the League Two title in the 2016-17 season.
After sticking rigidly to a 4-2-3-1 formation, the move was executed with little preparation and the Blues were 3-0 down in 46 minutes.
It proved to be Pompey’s only defeat in a 12-match charge to the League Two title.
But wing-backs hasn’t always been bad news for the Blues.
Who can forget Harry Redknapp’s men storming to the Division One title in the 2002-03 campaign?
Pompey were 2-0 down at Crystal Palace in their third league game when Redknapp switched to a wing-back system.
Three goals in four second-half minutes then turned the game on its head, and the 3-5-2 formation provided the framework for one of the most memorable seasons in the club’s history.