The versatile West Ham youngster will tie up a loan move to Fratton Park and go straight into the squad for Saturday’s visit of Scunthorpe.
The 19-year-old, who has made 11 appearances for the Hammers, is a left-footed player who normally operates in the centre of defence.
However, Guy Whittingham has earmarked him to fill the left-back spot which has proven troublesome for the Blues so far this season.
The past two matches have seen both Joe Devera and Danny East operate there.
Yet neither are naturally left-footed, affecting the balance down that flank.
Meanwhile, Marcos Painter has been hampered by injury since his arrival in August.
Despite being an unused substitute in the past three matches, there remain on-going concerns over the 27-year-old’s availability in the long-term, with his contract up for renewal in January.
Shaun Cooper is another alternative, while Dan Butler is currently on loan at Aldershot.
Those issues have persuaded Whittingham to recruit a new left-sided full-back and Potts is the player he has identified.
The son of former West Ham defender, Steve, he is an England under-20 international and spent part of last season on loan at Colchester.
At the Weston Homes Community Stadium he made five appearances, before being recalled by the Hammers in January and thrust into their first team.
Potts played against Manchester United in the FA Cup last term, as well as featuring against both Sunderland and Arsenal in the Premier League.
Yet, during the current campaign, his sole appearance came in a 2-0 Capital One Cup victory at Burnley last month.
Pompey’s board gave Whittingham the go-ahead to strengthen his squad following Monday night’s special meeting – in the aftermath of the AFC Wimbledon debacle.
With John Marquis having returned to Millwall at the end of his two-month loan, finances have been juggled to allow the Blues boss to make another signing.
Saturday’s visit of Scunthorpe now represents a crucial fixture, and Potts will be a likely starter once his deal is rubber-stamped.
Whittingham and first-team coach Alan McLoughlin scouted the Iron last night in their FA Cup replay against Grimsby.
The non-leaguers picked up a shock 2-1 victory at Glanford Park to inflict more gloom on a side who lost to Accrington at the weekend.
Pompey’s preparations for the fixture have also seen today’s traditional day off scrapped and players called in for training.
Yet there remain doubts over Patrick Agyemang after he came off against Wimbledon having aggravated an injury in his left thigh.