And it's to Galway that the national selectors will travel, from their base in Limerick, to see how their current squad members perform just a little over a week away from when they'll announce the RWC squad.
They will be studying a video of the action from Ravenhill where Ulster play a London Irish side that will include Justin Bishop who, along with home wing Tyrone Howe, must still entertain hopes of squeezing into O'Sullivan's squad.
Meanwhile, Leinster continued their pre-season preparation with a comfortable 41-13 victory over Coventry at Coundon Road last night. Two tries in the space of three minutes from John McWeeney put the game in safe keeping by the end of the first quarter and there were also tries for Gary Brown and Niall Ronan to leave the visitors 24-13 in front at the interval.
Leinster closed it out with second half tries from replacements Brian Blaney and Brendan Burke with prop Peter Coyle scoring the final try.