The Official Online RBS 6 Nations Store is open. The store has everything you need to get behind your team during the RBS 6 Nations, plus the store is now fully stocked with a much wider range of rugby merchandise.
John Yapp (dead leg), Taufa'au Filise (ankle) and Richard Mustoe (shin) are also struggling after Saturday's game.
Xavier Rush (dislocated finger) is also missing, Maama Molitika (chest) will be out for three-to-four months, but Tom James is fit for the first time this season.
The Wales wing has been sidelined since Wales' summer tour of North America with groin and shoulder problems.
Roberts' comeback game against Connacht the week before the Scarlets match also saw him injured, his ankle problem turning out to be not as serious as first feared.