(Reuters) - England lock Courtney Lawes will miss the rest of the Six Nations after suffering a calf strain during Saturday's defeat by Wales, the Rugby Football Union (RFU) said.
The 30-year-old had to be helped off the field in Cardiff and a subsequent MRI revealed the damage.
"Lawes is expected to be out for a minimum of four weeks. He will return to his club for rehabilitation," RFU said in a press release.
England's hopes of completing the Grand Slam were dashed following the 21-13 defeat by Wales.
(Reporting by Andrew Both in Cary, North Carolina, editing by Pritha Sarkar)