The former Charlton and West Ham youngster is back training with the Blues – two weeks after being initially told the club would not be signing him.
He was released on the same day as goalkeeper Corey Addai, after appearing in pre-season games for Danny Cowley.
The News understands that the Pompey boss always intended to revisit a move for Mingi.
And while no deal is imminent, he is seen as someone who could fit into the ‘young players’ category Cowley wants on the periphery of his first-team squad.
At present, only Liam Vincent and Jayden Reid have been added to the Blues’ ranks in that capacity.
Twenty-year-old Mingi is under the Pompey microscope after leaving Charlton this summer with the midfielder initially coming through the ranks at West Ham.
That takes his outlay on midfielders to four this summer, with both Shaun Williams and Ryan Tunnicliffe arriving earlier in the transfer window.