England lock George Kruis has been ruled out for the remainder of the Six Nations due to a knee injury.
The 26-year-old missed the opening match of England's defence - a narrow 19-16 win over France - having sustained knee ligament damage earlier this week.
The Saracens forward will now undergo surgery on the problem which will keep him out for up to 12 weeks, also putting his British and Irish Lions hopes in jeopardy.
"George will undergo surgery on Tuesday for a knee ligament injury sustained in training earlier in the week," read a statement from the Rugby Football Union.
"It is expected that the second row will require a 10-12 week rehabilitation period."
Joe Launchbury replaced Kruis alongside Courtney Lawes for the win over France.
