Sexton will miss this weekend's Rainbow Cup game against Connacht.
It’s almost a month since Sexton suffered his latest blow to the head in the Heineken Champions Cup quarter-final win over Exeter.
Meanwhile, Rhys Ruddock has been ruled out for up to six weeks with a calf injury.
Ulster will be without John Cooney and Robert Baloucoune for Friday’s Rainbow Cup meeting with Munster.
Both players are observing the return-to-play protocols having suffered concussions in the Challenge Cup defeat to Leicester.
Meanwhile, Munster confirmed today that RG Snyman requires a procedure on his knee.
The South African lock suffered a setback in his return from an ACL injury.
Snyman hasn’t played since sustaining the injury in his debut match in August.