Captain Johnny Sexton and wing Jordan Larmour are expected to be fit for Ireland's opening game of the Six Nations against Scotland.
Wales full-back Liam Williams will miss the first game of the Six Nations against Italy but uncapped teenager Louis Rees-Zammit is expected to be fit.
Ulster centre Stuart McCloskey has been called up to Ireland's squad for the Six Nations.
Jack Nowell has not been included in the England Six Nations squad, with Eddie Jones calling up eight uncapped players.
Billy Vunipola is a major doubt for England's Six Nations campaign after sustaining a suspected broken arm on Monday (AEDT).
Jacques Nienaber had previously served as Rassie Erasmus' assistant with South Africa and has now taken the top job.