From Thursday, the Blues’ boss will be unavailable for managerial duties, ruling him out of match-day attendance and training sessions.
Instead assistant manager Joe Gallen will oversee Pompey in a caretaker capacity, aided by first-team coach Jake Wigley.
However, Jackett will remain at the helm for Tuesday night’s trip to Bristol Rovers in League One.
In a statement, the club revealed plans for the 59-year-old to take a short break from the club.
However, precise details behind the ‘medical procedure’ have not been revealed.
In a statement, Pompey said: ‘Portsmouth Football Club can advise that, with effect from this Thursday (February 18), Kenny Jackett will not be in attendance at matches or training sessions following a medical procedure that will require a short period of rest and recuperation.
‘Assistant manager Joe Gallen will operate in a caretaker capacity during this time and will be assisted by first team coach Jake Wigley.
‘Kenny will remain in constant contact with them both, while also able to speak to the players via video link before and after games, as well as at half-time.
‘We wish Kenny a speedy recovery and look forward to seeing him back shortly.’
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