Leinster have added Ross Byrne to their Champions Cup roster and de-registered the injured Cathal Marsh ahead of Friday night's Champions Cup game against the Northampton Saints at Franklin's Gardens (7.45).

The 21-year-old former St Michael's College pupil and Ireland Under-20 captain is likely to be on the bench for that match if Jonathan Sexton is ruled out as anticipated. Joey Carbery is likely to start in Northampton.

Ulster also made one change to their squad for the Champions Cup with South African born prop Wiehahn Herbst, who signed a new two year contract on Wednesday with the province that will keep him there until the summer of 2019, replacing short term signing, Georgian Anton Peikrishvili who was injured throughout his stay before moving on. Herbst becomes Irish qualified next year.