London - Uncapped Worcester backrow Matt Kvesic was among three players added to England's Six Nations squad on Sunday as injuries took a toll on several of coach Stuart Lancaster's original selections.
Also summoned were Harlequins wing Ugo Monye and Saracens lock Mouritz Botha who both won the last of their England caps in November, against Fiji and South Africa respectively.
Kvesic joined what is now a 34-man squad as injury cover for Exeter's Tom Johnson (knee) while Botha comes in for Northampton's Calum Clark (shoulder).
Both Johnson and Clark, injured during weekend European Cup ties, will remain at their clubs for treatment, according to a Rugby Football Union statement issued Sunday.
"I have been fortunate to have a run of games at Warriors, and now I am delighted to get the call from England," the 20-year-old Kvesic, born in Germany, told Worcester's website.
"It would be fantastic to get the opportunity to feature in the Six Nations, but my priority now is meeting up with the team, keeping my head down and working hard to try and make that a reality."
Monye will join the squad as cover while players who were in European Cup action are assessed by England's medical team.
Johnson went off just 13 minutes into Exeter's game against Leinster on Saturday and looks unlikely to be fit for England's opening two Six Nations matches, against Scotland and Ireland, next month.
Clark was named in the England squad earlier this month, having being banned for a mammoth 32 weeks from March to November last year for "hyper-extending" Leicester hooker Rob Hawkins's arm during the Anglo-Welsh Cup final.
England begin their 2013 Six Nations campaign against Scotland at Twickenham on February 2, with Lancaster's men looking to build on their shock 38-21 home win over world champions New Zealand last time out in December.
Revised England Six Nations squad
Backs: Chris Ashton (Saracens), Brad Barritt (Saracens), Mike Brown (Harlequins), Freddie Burns (Gloucester), Danny Care (Harlequins), Lee Dickson (Northampton), Owen Farrell (Saracens), Toby Flood (Leicester), Ben Foden (Northampton), Alex Goode (Saracens), Jonathan Joseph (London Irish), Ugo Monye (Harlequins), David Strettle (Saracens), Manu Tuilagi (Leicester), Billy Twelvetrees (Gloucester), Ben Youngs (Leicester)
Forwards: Mouritz Botha (Saracens), Alex Corbisiero (London Irish), Dan Cole (Leicester), Tom Croft (Leicester), Dylan Hartley (Northampton), James Haskell (Wasps), Matt Kvesic (Worcester), Joe Launchbury (Wasps), Courtney Lawes (Northampton), Joe Marler (Harlequins), Ben Morgan (Gloucester), Geoff Parling (Leicester), Chris Robshaw (Harlequins), Mako Vunipola (Saracens), Thomas Waldrom (Leicester), David Wilson (Bath), Tom Wood (Northampton), Tom Youngs (Leicester)