Pompey are interested in former Northampton midfielder Danny Rose.
The 28-year-old helped the Cobblers to the League Two title last season, after joining the club midway through the season from Oxford.
A new deal had been offered to the player, with his short-term deal at Sixfields due to epxire.
However, Northampton have now confirmed that they will not be signing Rose.
A Blues medical has already been arranged, with Rose at Pompey today as Paul Cook looks to complete his frist signing of the summer.
The manager has already been busy attempting to freshen his squad up for the 2015-16 season, with interest expressed in Chesterfield’s Jay O’Shea, Huddersfield’s Duane Holmes and former Pompey loanee Kieron Freeman.
Matt Clarke is also set to make his loan spell at the Blues permanent after being part of the deal that will see Adam Webster move to Ipswich.