England flanker Sam Underhill will not feature in the Test series decider against Australia due to concussion, joining Maro Itoje on Eddie Jones' list of absentees.
Jones confirmed Itoje would be unavailable for the winner-takes-all clash in Sydney on Saturday, after England levelled the series with a 25-17 victory in Brisbane last weekend.
England have won four of their past five games in Oceania, having done so just once in their previous 12 away matches against teams from that continent, but the most recent victory came at a cost.
While Jones had already acknowledged Itoje would miss the third Test, England remained hopeful Underhill may be fit to feature after the pair both suffered concussions in the same game.
However, England announced on Monday that the pair had been withdrawn from the squad and no replacements have been called up.
Flanker Tom Curry has already returned home after being concussed in the first Test, with Australia's Jordan Petaia and Allan Alaalatoa making up the five players ruled out of the series due to concussion.
Jones will likely call upon Billy Vunipola and Courtney Lawes again, with Ollie Chessum, Lewis Ludlam and Jack Willis the alternate options for the final spot in the back row.