Leinster coach Leo Cullen has included Eoin Reddan to start beside Johnny Sexton in the half backs for their meeting at home with Treviso.
In the pack Mike Ross replaces Tadhg Furlong while Jordi Murphy takes over from the injured Josh Van Der Flier in the back row.
A win for Leinster will ensure a home semi final.
Ulster are away to Ospreys knowing they need a win to make sure of a place in the semi final.
There's just one change to the team that beat Leinster last week with Craig Gilroy taking over from Rory Scholes on the wing.
Leinster v Treviso in the RDS, Saturday May 7 - kick-off 3pm.
Leinster team: 15. Rob Kearney,14. Isa Nacewa - capt.,13. Garry Ringrose, 12. Ben Te'o, 11. Dave Kearney, 10. Johnny Sexton, 9. Eoin Reddan; 1. Jack McGrath, 2. Richardt Strauss, 3. Mike Ross, 4. Devin Toner, 5. Mick Kearney, 6. Rhys Ruddock, 7. Jordi Murphy, 8. Jamie Heaslip.
Replacements: 16. Sean Cronin, 17. Peter Dooley, 18. Tadhg Furlong, 19. Ross Molony, 20. Dominic Ryan, 21. Luke McGrath, 22. Cathal Marsh, 23. Noel Reid.
Ospreys v Ulster in the Liberty Stadium, Saturday May 7 - kick-off 3pm.
Not long now... pic.twitter.com/Q7DGLHSqEb— Ulster Rugby (@UlsterRugby) May 6, 2016
Ulster team: (15-9) J Payne; A Trimble, L Marshall, S McCloskey, C Gilroy; P Jackson, R Pienaar; (1-8): C Black, R Best (c), R Lutton, P Browne, F van der Merwe, I Henderson, C Henry, S Reidy;
Replacements: (16-23) R Herring, K McCall, A Warwick, R Diack, R Wilson, P Marshall, S Olding, D Cave.