England forward Courtney Lawes has been ruled out for 12 weeks with an ankle injury, the Rugby Football Union (RFU) confirmed on Wednesday.
England coach Eddie Jones is already navigating a convoluted Six Nations schedule with his training squad minus any players from Bath, Sale, Bristol, Exeter, Worcester or Wasps due to the end of season run in.
It led to him calling up 12 uncapped players out of 28 for their latest get-together, but he will not be able to count on Lawes for their remaining Six Nations match against Italy, or the Autumn Nations Cup.
Lawes was forced off injured in Northampton's Round 21 defeat to Sale, the same match that saw Manu Tuilagi sidelined for six months with an achilles injury. Lawes has been an integral part of the England squad under Jones, playing both in the back-row and in the second-row.
It adds to a growing number of Northampton players absent with both Piers Francis and Lewis Ludlam both unavailable as they are self-isolating in line with COVID-19 protocols after they played Sale, who registered 19 positive coronavirus results last week.