England prop Mako Vunipola will be sidelined for around 10 days with minor hamstring complaint.
The Rugby Football Union (RFU) confirmed Vunipola sustained “a small tear of scar tissue” while featuring as a second-half replacement during Saturday’s 57-15 win over Ireland at Twickenham.
News of a small setback comes as a relative boost to England coach Eddie Jones after the Saracens front row was ruled out for three months with a hamstring injury in May – the Ireland game marking his return to action.
Exeter Chiefs’ Ben Moon will join up with the squad at their training base in Treviso as a temporary replacement.
Moon’s club team-mate Jack Nowell could miss the Rugby World Cup as he battles to overcome an ankle problem
Nowell has not featured in any of England’s three warm-up Tests to date and was named in the 31-man squad despite suffering his injury during the Premiership final defeat to Saracens in June.
“I think he’s going to be touch and go for involvement in the World Cup,” Exeter director of rugby Rob Baxter told BBC Radio Devon.
“But let’s cross our fingers and hope that he can come through.”
England play their final warm-up game against Italy at St James’ Park next Friday before heading to Japan two days later on September 8.
Jones’ men begin their World Cup campaign against Tonga on September 22.