England have suffered a pre-World Cup scare with an injury to Wasps back-row forward Brad Shields.
Shields is to return home from England's training camp in Italy after suffering a foot injury.
Harlequins' uncapped back-row prospect Alex Dombrandt will join the squad as Shields' replacement.
The Rugby Football Union said: "The back-rower will replace Brad Shields (Wasps), who returns home this morning after picking up a foot ligament injury.
"Shields will undergo further assessment in England to understand the extent of the injury."
England head coach Eddie Jones now faces an anxious wait to discover the extent of 28-year-old Shields' problem.
The New Zealand-born player has won eight caps and featured in three of England's games during last season's Six Nations.
Jones and his players are in Treviso for an intensive training camp, with Shields a strong candidate to make the final World Cup squad.
That 31-man group is due to be announced on August 12, a day after England's opening World Cup warm-up game against Six Nations champions Wales at Twickenham.
Dombrandt, 22, has previously trained with England this summer and is rated as an outstanding prospect.
