Republic of Ireland international goalkeeper Colin Doyle is training with Pompey.
The former Bradford keeper has linked up with the Blues for a week after failing to agree terms on a new deal at Valley Parade.
The Bantams said they had offered the 33-year-old a new two-year contract on the same terms as his previous deal, which expired this summer.
But Doyle, who made 88 appearance for Bradford following his move for £1 from Blackpool two seasons ago, found out negotiations had come to an end while on holiday with his family in the Dominican Republic.
He finished the 2017-18 campaign playing in the Republic of Ireland’s end-of-season friendlies against France and the USA.
The Cork-born keeper has four international caps.
Pompey have already dipped into the transfer market this summer, signing Craig MacGillivray on a free transfer from Shrewsbury.
His arrival increased the competition for the Blues’ No1 jersey, with Luke McGee making 50 appearances last term following his arrival from Spurs.
Alex Bass, fresh from signing a new three-year deal at Fratton Park, this week joined Torquay on a season-long loan.