Pompey have signed midfielder Stuart O’Keefe from Cardiff on a season-long loan, subject to international clearance.
The 26-year-old has previously helped Crystal Palace win promotion from the Championship and featured for them in the Premier League.
Blues boss Kenny Jackett said: “We’re very pleased to bring Stuart in for the rest of the season.
"He brings experience and aggression into our midfield."
“He brings experience and aggression into our midfield and will complement the young ball-playing guys in that area of the pitch.”
O’Keefe progressed through the ranks at Southend before joining the Eagles and then arriving at Cardiff in 2015.
He has scored twice in 45 appearances for the Welsh club and appeared against Pompey in the Carabao Cup earlier this season.