Uncapped Northampton lock Christian Day and Leicester flanker Tom Croft have been added to the senior training squad for the Six Nations in England.
The pair join the squad after Tom Wood and Geoff Parling were injured while playing on Saturday for their teams.
England have several injury worries, with Owen Farrell (knee), Kyle Eastmond (shoulder) and Brad Barritt (knee) hurt.
Luther Burrell is anticipated to participate in training on Friday.
Burrell is recuperating from the concussion he suffered against Racing Metro in the loss of Northampton.
His teammate, flanker Wood, injured his ankle during the defeat, while Leicester lock Parling left the field using a knee injury three minutes in their defeat by Ulster which Tigers director of rugby Richard Cockerill considers could keep him out for “three to four weeks”.
A 34-guy England training squad met on Monday to prepare for their opening Six Nations match against Wales in Cardiff on Friday, 6 February.
England head coach Stuart Lancaster said he’d have the ability to offer an update on Farrell – who’ll find a specialist on Monday – and his other wounded players on Tuesday.
“The players will be completely evaluated once they get into camp and it is too early to give any authoritative news on their status,” he said.
The 2nd row will probably be an area of special issue for Lancaster, who’s already without locks Joe Launchbury (neck) and Ed Slater (knee) for the whole tournament, while Courtney Lawes has had mild ankle operation that has ruled him out until the center of the effort in the earliest.