Two of England's most important players were due before disciplinary hearings, Farrell this morning and Vunipola this evening. The Saracens pair would leave a sizeable hole in England's World Cup plans if suspended.
Farrell was due before an appeal hearing after World Rugby contested the rescinding of his red card for a high tackle on Wales's Taine Basham. Vunipola is facing a disciplinary committee for his own red card for a high tackle on Andrew Porter in Saturday's defeat by Ireland.
Farrell would miss the whole of England's pool matches should he receive a six-week ban, while Vunipola could anticipate a suspension in the region of three to four weeks should his dismissal be upheld.
England's preparations ahead of hosting Fiji on Saturday have been hit by the hearings, though head coach Steve Borthwick could look to rotate his line-up.
Twickenham could be only half-full, with ticket sales around the 40,000 mark. New Zealand's clash with South Africa at HQ on Friday is on course to be a sell-out.