Sydney (AFP) - England flanker Sam Underhill was Monday ruled out of the crunch third Test against Australia with concussion, while the Wallabies called up replacements to their injury-depleted squad.
Underhill only played in the second Test at Brisbane, that England won 25-17, after Tom Curry returned home after a head knock in a bruising first match at Perth where the Wallabies triumphed 30-28.
He joins Maro Itoje on the sidelines with the big lock already scratched from this weekend's deciding Test after he also suffered a concussion in Brisbane.
England said no replacements would be jetted in with Lewis Ludlam set to join Courtney Lawes and Billy Vunipola in the starting back row.
The Wallabies are also severely depleted with nearly a third of the 35-player squad named ahead of the three-match series succumbing to injury or suspension.
They drafted in winger Mark Nawaqanitawase and flanker Lukhan Salakaia-Loto on Monday.
Nawaqanitawase comes in with fullback Jordan Petaia unlikely to feature in Sydney after he was yet another concussion victim.
Wing Izaia Perese (knee) remains a doubt while backs Tom Banks (broken arm) and Andrew Kellaway (hamstring) are out.
Salakaia-Loto was called up with Cadeyrn Neville struggling with a knee injury while lock Darcy Swain is serving a suspension for a red card in Perth.
The Wallabies remain hopeful ACT Brumbies duo Allan Alaalatoa (concussion) and Len Ikitau (calf) will be available for Sydney.