James Haskell and Jack Clifford have remained in England for treatment as the rest of the training squad flew to Portugal for a warm weather training camp ahead of the start of the RBS 6 Nations.
The pair were both injured at the weekend and will face medical checks to see when they will be able to join up with the squad, the Rugby Football Union said.
Neither are thought to be seriously hurt and both should remain part of the 34-man squad named by head coach Eddie Jones last Friday (January 20th).
The squad includes three new faces. These include 29-year-old Bath Prop Nathan Catt, who has played for England at Under 18, Under 19, Under20 and Saxons levels. Leicester Tigers flanker Matt Williams is also involved and will hope to fare rather better than when he was called up to the 45-man England training squad last August, when he promptly suffered a broken arm. Finally, Wasps number 10 Alex Lozowski, whose father Rob was capped once by England in 1984, will hope to make his first appearance in an England shirt after being part of the squad last year. Eddie Jones has described him as the "find of the Premiership".
Haskell will certainly be champing at the bit to get back in the side, following a difficult recovery from a broken toe suffered against Australia last year.
Speaking to the BBC Radio 5 Live Rugby Union Weekly Podcast, he said: "It's been the hardest six months of my professional career, there was a time when I thought I was never going to make it back."
"There were a lot of sessions where I would take three steps forward and two steps back, but we got there in the end."
Haskell admitted he felt some discomfort in his recent comeback match between Wasps and Zebre, but acknowledged that "you are always going to have that" after such an injury.
While the squad will hope to carry out some fine-tuning in Portugal, fans booking corporate hospitality for the upcoming games at Twickenham against France on February 4th, Italy on February 26th and Scotland on March 11th will be hoping to see three victories as England chase a second successive Grand Slam, a feat that would take them to 19 successive Test victories and thus overtake the record of 18 wins set by New Zealand only last year. The biggest test is likely to come in Dublin against Ireland, who ended the All Blacks' run in Chicago last year, their first ever win over New Zealand, as well as defeating Australia in the autumn.
Eddie Jones will be relying on competition for places to ensure his squad has the strength to deal with all the challenges it faces. It coped with an injury crisis in the autumn and may have to do so at some point in the 6 Nations.
Squad depth is one matter, but Jones has also courted controversy by telling the BBC last week the side has "no world class players yet", a barb that may encourage his players to reach yet greater heights following a stellar first year under the Australian.