Pompey have reached an agreement with Derry City to sign Ronan Curtis.
The 22-year-old winger has penned a pre-contract two-year deal and is set to officially become a Blues player on June 9 when the international transfer window reopens.
Curtis – who has represented Republic of Ireland up to under-21 level – will join for an undisclosed fee.
Assistant manager Joe Gallen said: “He’s someone we’ve tracked for the past few months. He’s got a lot of pace and power, and is good in the air as well, so we’re really pleased to bring him here.”