England have suffered a double injury blow ahead of their Six Nations clash against Ireland, after Nathan Hughes and Courtney Lawes were ruled out of the Twickenham showdown where Ireland are playing for a Grand Slam title.
The back row forwards sustained knee problems in the 22-16 defeat by France in Paris and have been omitted from a 32-man training squad that is to prepare for the final round of the Championship.
Hughes limped off in the 24th minute at the Stade de France after taking a heavy blow to his left knee, but Lawes was able to complete the match. Both players are to undergo scans on Monday.
Exeter's hard grafting Don Armand has been drafted into the squad as cover and given the injury problems in the back row, could play a role against Ireland.
Armand won his only cap as a replacement during last summer's tour to Argentina but then fell out favour with Jones, who was uncertain over his suitability for Test rugby and has faced repeated calls for his inclusion ever since.
Nick Isiekwe and Charlie Ewels are present to provide depth at lock, a position which is also affected by the loss of Lawes.
Having lost two starting back rows, the path is clear for James Haskell and Sam Simmonds to be promoted from the bench duties they performed against France.
With Jones seeking more power at the breakdown, however, and indicating on Saturday that he is considering making changes to this effect, Simmonds could see his chance of being on from kick-off recede.
England are expected to provide an update on the fitness of Dylan Hartley on Monday after the captain was ruled out against France by a tight calf.