England will be without Maro Itoje during the end-of-year internationals after the Saracens lock was ruled out for six weeks due to a fractured right hand.
There were fears Itoje could sit out the Tests against South Africa, Fiji, Argentina and Australia after he was injured during Saturday's 44-26 European Champions Cup win over Scarlets.
Premiership and European champions Sarries on Monday confirmed the versatile Itoje suffered a break and requires surgery.
The club's director of rugby Mark McCall said: "For any team to lose a player of the ability of Maro is a blow and he will be missed through the autumn for both Saracens and England.
"What's now important for Maro is his recovery and we look forward to his return later this season."
The absence of the influential 21-year-old, who has emerged as a key man for club and country, is a major blow to England head coach Eddie Jones, who already had a lengthy injury list to contend with.
Itoje's Sarries and England team-mate George Kruis is among those sidelined after he underwent ankle surgery last week.
England play the first of four Tests at Twickenham in as many weeks against South Africa on November 12.