Pompey have signed Damien McCrory on loan from Burton until January.
The 27-year-old Irishman is primarily a left-back, but can also be utilised in a more advanced position.
Blues boss Kenny Jackett said: “He’s an experienced player who provides competition for Brandon Haunstrup in that role.
“It’s a specialist position and we’ve been looking to bring someone in since Tareiq Holmes-Dennis’ unfortunate injury on the opening day.
"He’s an experienced player who provides competition for Brandon Haunstrup."
“He’s won promotion from this division before and has also played in the Championship, so we’re delighted to bring him in on loan.”
McCrory started his career at Plymouth and enjoyed a successful stint with Dagenham before joining Burton in 2012.
He has made almost 200 appearances for the Brewers and represented Republic of Ireland at youth level.