
The news will be confirmed later today at a press conference and heap more pressure on under-pressure Pompey boss Paul Hart.
The Premier League strugglers lost their opening seven games of the season — the worst start in the competition's history — but won their first points of the campaign by beating Wolves 1-0 last weekend.
The south coast club remain bottom of the table but are under new ownership after billionaire Saudi businessman Ali Al-Faraj bought Sulaiman Al-Fahim's controlling stake earlier this week.
In June 2006, Grant took the role of technical director at Fratton Park, but left to join Chelsea as director of football a year later.
The Israeli replaced Jose Mourinho as Chelsea boss in September 2007, but failed to win any silverware with the Blues and parted ways with the Londoners in May last year.
Grant's return to Portsmouth will be his first role in football since leaving Stamford Bridge.
slowly he will get the manager post again