Lee Bradbury has emerged as an early contender for the Pompey job.
Yet The News understands it would require a five-figure fee to prise him away from the Hawks.
That is the clause in the contract of the former Fratton favourite, who is less than a month into his job at Westleigh Park.
Bradbury left a role coaching under-14s in Pompey’s Academy to take on the Hawks role.
The association with Bradbury for the Blues’ vacancy following the exit of Michael Appleton is an obvious one.
The former striker spent six-and-a-half years in total at Fratton Park.
He recently took over as boss of the Hawks, yet within a week, vice-chairman Jim Fallon pulled out of the club, putting the pressure on them financially.
In the past, Bradbury has made no secret of his desire to one day take over at Fratton.
His first managerial job came at Bournemouth in January 2011 when Eddie Howe left for Burnley.
Bradbury took over the reins and led the Cherries to the play-off semi-finals that season, where they lost to Huddersfield on penalties.
His 15-month tenure came to an end in March, when Paul Groves was initially appointed as caretaker manager.
Bradbury declined to comment on the Pompey situation when contacted.