All four Irish sides are in action over the weekend.
Adam Byrne will start his first game for Leinster in almost two-years when they host Zebre in the United Rugby Championship tomorrow.
The Ireland capped winger has been sidelined with a succession of injuries since December 2019.
Jordan Larmour also returns from injury to start on the other wing at the R-D-S, with Jimmy O’Brien making his first appearance of the season at full-back.
Flanker Dan Leavy and out-half Harry Byrne have also been handed their first starts of the campaign.
Connacht head-coach Andy Friend has made three changes for his team's clash with the Dragons tomorrow.
Matthew Burke, Ben O’Donnell and Ireland international Paul Boyle come into the side for the game at the Sportsground.
Burke joins Finlay Bealham and Dave Heffernan in the front-row with Boyle coming in at number-eight.
Wing O'Donnell gets his first start of the campaign in a back-three which also includes Mack Hansen and Tiernan O'Halloran.
Munster have made 11 changes for their trip to the Scarlets in the United Rugby Championship tomorrow.
Matt Gallagher, Liam Coombes and Neil Cronin all make their first appearances of the season in the Reds' backline while flanker Jack O'Donoghue skippers the side.
Ben Healy comes in to start at out-half as head-coach Johann van Graan shuffles his pack after wins against the Stormers and Sharks.
Ireland hooker Rob Herring will play his 200th game for Ulster when they take on Benetton in Belfast this evening.