The Senegal centre-back will miss Wednesday’s league outing at the Stadio Diego Armando Maradona due to an injury he picked up on Sunday
The 29-year-old defender suffered the injury in Sunday’s 2-0 loss to Lazio and was replaced by Kostas Manolas in the 55th minute.
On Monday, the Senegal international underwent medical tests which confirmed a pulled thigh muscle in his left leg and his expected to be out for at least 10 days.
Koulibaly’s injury update might come as a worry for Gennaro Gattuso, who will miss a key force in his defence when they host 18th-placed Torino at the Stadio Diego Armando Maradona.
After back-to-back defeats to Inter Milan and Lazio in the Italian top-flight, Napoli will aim to bounce back to winning ways and grab their first win since their 2-1 home win over Sampdoria on December 13.
At the end of his 10-day recovery programme, the centre-back will be reassessed before he links up with the first team.
“Kalidou Koulibaly underwent tests on Monday which confirmed he sustained a pulled left thigh muscle in the 2-0 defeat to Lazio on Sunday,” read the club statement.
“The player has already started his recovery program and will be reassessed in ten days.”
Koulibaly has played 18 matches for the Parthenopeans across all competitions, which include 12 appearances in Serie A and six in the Uefa Europa League.
Napoli will be hoping to have the 29-year-old back in contention for their next league fixture against Cagliari on January 3 alongside Nigeria’s Victor Osimhen, who is still recovering from a dislocated shoulder.
They are currently fifth on the Serie A table with 23 points after 13 matches.