Donnacha Ryan faces his former Munster teammates with Racing on Sunday but he won't let sentimentality get in the way of his side's quest for a first Champions Cup title.
Ulster stayed in the race to make the Guinness PRO14 play-offs by claiming a 36-15 bonus point victory over Glasgow at the Kingspan Stadium in their last regulation season home game.
Ospreys were easily beaten 37-14 at Zebre, paying the expected price for making 13 changes in their PRO14 clash.
Northampton Saints' Wallabies centre Rob Horne has been forced into retirement just seven days after suffering nerve damage to his right arm.
Cardiff Blues secured their passage to the Challenge Cup final with a hard-fought 16-10 victory over Pau at the Arms Park.