If the report is accurate, the loss of O'Sullivan would be the hardest to absorb.
Against a Dutch side that usually wants long spells of possession, Ireland’s ability to compete in central areas matters most. Without their usual balance there, the game could become stretched, and that tends to favour technically cleaner teams.
The report also says Emily Murphy will miss out, with Abbie Larkin the likely replacement.
There is at least one balancing factor for Ireland. The Dutch are also reported to be without Vivianne Miedema, a major absence given her international scoring record. That does not make the Netherlands easy to face, but it does remove a proven match-winner.
There is another layer to the night.
That tension could shape every duel, especially if the match tightens late on. Ireland still have a path, but it appears narrow. Friday’s contest now looks like the kind of qualifier that can define a campaign - and with Grenoble to come next, every decision may carry consequences beyond one night.