This has been seen the most in the midfield department, with Ryan Tunnicliffe and Jay Mingi the only pair fit to feature against Forest Green on Saturday.
That's after problems with Louis Thompson, Tom Lowery, Marlon Pack and Joe Morrell have whittled the Blues engine room to just two available faces.
Indeed, Danny Cowley could be faced with another challenge should Morrell receive a call-up for Wales in the upcoming World Cup.
The Blues boss has previously written off the possibility of strengthening his squad through the free agent market.
But if their injury situation in the middle of the park worsens, who could Pompey turn to if they need a short-term fix.
We’ve found seven midfielders, who are without a club, Cowley could eye should they explore the free agent market.
Indeed, Danny Cowley could be faced with another challenge should Morrell receive a call-up for Wales in the upcoming World Cup.
![Bostock was most recently at Doncaster but was released following their relegation to League Two in the summer. The 30-year-old has had spells in Belgium, France and Turkey and is on the lookout for his 15th career club after coming through the ranks at Spurs. The former Trinidad and Tobago international was reported to have been on trial with Nottingham Forest’s under-21s in September.](https://www.portsmouth.co.uk/webimg/b25lY21zOmI2YTVlYmVhLTFhOTMtNGE1ZS1hYjJjLWNlNTQ2Y2ViNjI5NDoyNTM1ZjU3OS02NmIzLTQ4NTgtYjY3Yi00NWY2NmEzZjIwYmI=.jpg?crop=3:2&width=640)
5. John Bostock
Bostock was most recently at Doncaster but was released following their relegation to League Two in the summer. The 30-year-old has had spells in Belgium, France and Turkey and is on the lookout for his 15th career club after coming through the ranks at Spurs. The former Trinidad and Tobago international was reported to have been on trial with Nottingham Forest’s under-21s in September. Photo: Alex Pantling
![The defensive midfielder was released at the end of his contract at Oxford in the summer after a four-year stay with the U’s. However, the 26-year-old featured just 61 times in the league for Karl Robinson’s side, two of which came last term. Hanson has been troubled by injuries during his career, which has seen him feature for Derby and Wigan.](https://www.portsmouth.co.uk/webimg/b25lY21zOjExNjFiZjg3LTljMzQtNDZlYy1iYjViLWI0ODNhNGRhNjM2ZDo5MWQwMzRkOC03NjVlLTRiNjgtOGE3My0yZDlhMDQwMWEwODg=.jpg?crop=3:2&width=640)
6. Jamie Hanson
The defensive midfielder was released at the end of his contract at Oxford in the summer after a four-year stay with the U’s. However, the 26-year-old featured just 61 times in the league for Karl Robinson’s side, two of which came last term. Hanson has been troubled by injuries during his career, which has seen him feature for Derby and Wigan. Photo: Pete Norton
![Just three-years-ago, Bacuna made a £4m switch from Reading to Cardiff after impressing during his two-year stay with the Royals. The 31-year-old was released by the Bluebirds in the summer after making 115 appearances, while scoring four goals for the Welsh outfit. Bacuna has been training with Birmingham as he goes in search of a new club.](https://www.portsmouth.co.uk/webimg/b25lY21zOmVjMDU5ZmRhLTg3ZWMtNDEwNS1iYzg2LWE1YzIwZWZmYmYxMjpiYmM4NTlhMC0zZWZkLTQ4OGUtYTMwZS02ZmJhNWNiMzdlYTQ=.jpg?crop=3:2&width=640)
7. Leandro Bacuna
Just three-years-ago, Bacuna made a £4m switch from Reading to Cardiff after impressing during his two-year stay with the Royals. The 31-year-old was released by the Bluebirds in the summer after making 115 appearances, while scoring four goals for the Welsh outfit. Bacuna has been training with Birmingham as he goes in search of a new club. Photo: Pete Norton