England captain Owen Farrell faces a race to be fit for the Six Nations after Saracens confirmed on Thursday the playmaker will be sidelined for three months due to ankle surgery.
Farrell has been given a recovery time of up to 12 weeks and could miss England's Six Nations opener against Scotland on February 5.
The 30-year-old limped off during last Saturday's rout of Australia with the injury and was already due to miss England's Autumn Nations Series clash against South Africa at Twickenham.
Farrell has been plagued by problems during the current run of internationals.
He was forced to self-isolate for the opener against Tonga only for his Covid-19 sample to belatedly be confirmed as a false-positive.
In his absence, Courtney Lawes captained England against Tonga and he will also take the armband for the Springboks clash this weekend.
Should Farrell's recovery be delayed, England boss Eddie Jones could recall the out of favour George Ford when he selects the Six Nations squad.
The outlook on Jamie George's knee damage is less severe, with the England and Saracens hooker expected to be out for eight to 10 weeks, potentially making him available for the Scotland showdown.