Loan duo Mahlon Romeo and Hayden Carter emerged as Danny Cowley’s favoured figures for the position during the 2021-22 season, but have already returned to their parent clubs.
Meanwhile, the former Sheffield United man’s own Fratton Park future has been thrown into doubt, after reports emerged that he was being monitored by a trio of League Two clubs.
So who could the Blues turn their attention to in order to fill the void?
We’ve scoured the Championship for players who struggled for game time in the position this season, and identified the Premier League youngsters who could be looking for a new home over the summer.
Here’s who we found.
So who could the Blues turn their attention to in order to fill the void?
5. George Tanner - Bristol City
Age: 22 2021-22 Championship appearances:1 Picture: Nathan Stirk/Getty Images
Photo: Nathan Stirk
6. Nico Gordon – Birmingham
Age: 20 2021-22 Championship appearances: 11 Picture: Marc Atkins/Getty Images
Photo: Marc Atkins
7. Jayden Bogle - Sheffield United
Age: 21 2021-22 appearances:17 Picture: Alex Pantling/Getty Images
Photo: Alex Pantling
8. Bali Mumba - Norwich City (on loan at Peterborough)
Age: 20 2021-22 Championship appearances:10 Picture: Mark Thompson/Getty Images
Photo: Mark Thompson