Ulster captain Rory Best returns for Sunday's crucial European Cup clash at Gloucester after making a dramatic recovery from an ankle injury.
The hooker, named in the Ireland squad for the RBS 6 Nations, is one of eight changes made by caretaker coach Steve Williams despite Best not being expected to return to action for another couple of weeks, after injuring his ankle in the Boxing Day clash against Leinster in Dublin.
Gloucester welcome back wing Lesley Vainikolo in a game they need just to draw to progress.
The former rugby league star has recently been named in England's RBS 6 Nations squad but has not played since 29 December, after the death of his father.
Peter O'Mahony was named man of the match against England last month
21 April 2017, 7:22pm
Peter O'Mahony's performance in the RBS 6 Nations finale for Ireland against England was crucial to his selection for the British & Irish Lions on Wednesday, Ireland and Lions defence coach Andy Farrell has revealed.