Portsmouth manager Kenny Jackett will be absent from his side's matches and training sessions for a "short" but indefinite period after undergoing a medical procedure, the League One club has confirmed.
Jackett will oversee Tuesday's trip to Bristol Rovers but will be absent from Thursday onwards, with Saturday's home fixture against Blackpool the first game he will miss.
Assistant manager Joe Gallen will take temporary charge, with Jackett expected to address his players by video link both before and at half-time of matches.
"Portsmouth Football Club can advise that, with effect from this Thursday, 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," a club statement read.
"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."
Portsmouth are currently in the thick of the promotion race in League One, sitting in fourth place, just a point back from the top-two places that secure automatic promotion to the Championship.
Jackett's side are currently on a three-match unbeaten run having defeated Swindon last Tuesday before their weekend trip to Crewe was postponed due to bad weather.