Illness forces Rhys Webb to withdraw from today's derby clash against the Scarlets.
In a late change to the Ospreys line-up, scrum half Rhys Webb has withdrawn due to illness with Martin Roberts coming into the starting XV in his place.
Richard Fussell takes his place among the replacements.
Tom Grabham will now wear 21 and cover scrum half, with Fussell wearing 23.