Chancel Mbemba's facing at least a month on the sidelines, according to reports.
The Newcastle United defender was forced off in last night's international between DR Congo and Tunisia.
Mbemba – who scored in the World Cup qualifier – will be assessed fully when he returns to Tyneside.
However, a report in his home country has claimed he will miss DR Congo's next game against Libya on October 7.
United manager Benitez has fielded Mbemba at left-back with Paul Dummett sidelined with a hamstring injury.
The news on Mbemba is offset by the likely return of defensive pair Florian Lejeune and DeAndre Yedlin for Sunday's game against Swansea City at the Liberty Stadium.
Yedlin suffered a hamstring injury in pre-season, while Lejeune hurt his ankle in the club's season-opening defeat to Tottenham Hotspur.
Meanwhile, United manager Benitez hasn't been able to oversee training so far this week after undergoing a minor operation late last week.