Eoin Doyle is being linked with a return to Pompey.
The Lancashire Evening Post has reported that Paul Cook is keen to get the striker back on a permanent basis following his recent loan spell.
After signing in the January transfer window, the Irishman made 12 appearances for the Blues, scoring twice.
He missed the run-in to the League Two title after picking up a groin injury against Newport County at the end of March.
Cook and his coaching staff have been in Portugal since the season’s end but is expected back home this weekend.
During his time away, Pompey have been conncentrating on offering deals for their own out-of-contract players,
Kyle Bennett has signed a three-year deal, while Gareth Evans has signed on for a further two.