Pompey have been plagued with injuries across the back-line this season with captain Clark Robertson and Paul Downing facing lengthy spells on the sidelines.
This has seen the former Lincoln boss adapt to his personnel crisis by shoehorning midfielders and full-backs into a back-three.
And the Blues have suffered dearly as a consequence by conceding 11 goals in their last five league games.
However, it may not be as easy at it appears to bring new faces into the club with the January window notoriously difficult to operate in.
As a result, Cowley may have to look for a short-term fix by looking towards the free agents, or at those whose current deals are set to expire.
Click through the list to see who could arrive on the south coast on a free transfer or for a cut-price deal.
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9. Ryan Tafazolli: Wycombe
Tafazolli would be a welcomed addition in PO4 after making 20 Championship appearances last term. He's already racked up 11 in League One this season and the 30-year-old has been at the heart of Gareth Ainsworth's machine and is integral to their strong defence. (Photo by Nathan Stirk/Getty Images) Photo: Nathan Stirk
10. Michael Mancienne: Burton Albion
The 33-year-old is reaching the latter stages of his career but still has a lot to give. The former Chelsea academy graduate has been plying his trade for Burton Albion across the last two seasons but has only made six appearances this term. (Photo by Nathan Stirk/Getty Images) Photo: Nathan Stirk
11. Jason Pearce: Charlton Athletic
Former Blues defender Pearce could be eyeing a third spell at the club when his contract expires in the summer. Since his last tenure in PO4, the 33-year-old has played for Leeds and Wigan before arriving at the Valley and after making only six league appearances this term, a return could be on the cards. (Photo by James Chance/Getty Images) Photo: James Chance
12. Tom Flanagan: Sunderland
Tom Flanagan was one of four defenders to be swept aside by Pompey in early October, but has proved to be a solid option in League One. The 30-year-old has made 13 league appearances and has scored once in 2021/22 so far. (Photo by Pete Norton/Getty Images) Photo: Pete Norton