All four provinces have changed their registered squad's ahead of the return of European action this weekend.

South African centre Pat Howard replaces Johnny Holland as Munster's medical joker in their Champions Cup panel.

Head coach Anthony Foley says that they've got good strength in depth at the moment in the squad.

Meanwhile, Leinster have replaced Ed Byrne with Jamie Hagan, who they re-signed from London Irish on a short-term contract.

Ulster have been able to register fit-again Dan Touhy instead of Chris Henry.

Connacht have also made two changes to their squad for the Challenge Cup with new signings Bundee Aki and Tom McCartney replacing Tiernan O'Halloran and Jason Harris Wright respectively.