Back, 35 last month, would now appear to have a fight on his hands to prolong his international career and it could be that Richard Hill is switched to openside flanker for the Italian job.
Woodward stressed that the 28-strong group that assembles in Surrey had been selected on current form, with Leicester prop Graham Rowntree another experienced omission.
He said: "It is always hard to leave out such established international players as Back, Bracken, Corry and Rowntree but as always, I am looking at current form and will continue to do so throughout the Six Nations and beyond."
Nine players were not considered because of injuries including Jonny Wilkinson, Mike Tindall and Mike Catt.
Eight of England's young prospects have been invited to train with the senior squad. That contingent features Leicester scrum-half Harry Ellis and Bath prop David Flatman.
England's 28-man training squad for opening RBS 6 Nations game against Italy on February 15: I Balshaw (Bath), O Barkley (Bath), S Borthwick (Bath), B Cohen (Northampton), L Dallaglio (Wasps, capt), M Dawson (Northampton), A Gomarsall (Gloucester), P Grayson (Northampton), W Greenwood (Harlequins), D Grewcock (Bath), R Hill (Saracens), C Jones (Sale), B Kay (Leicester), A King (Wasps), J Leonard (Harlequins), J Lewsey (Wasps), H Paul (Gloucester), M Regan (Leeds), J Robinson (Sale), S Shaw (Wasps), J Simpson-Daniel (Gloucester), O Smith (Leicester), M Stevens (Bath), S Thompson (Northampton), P Vickery (Gloucester), D West (Leicester), T Woodman (Gloucester), J Worsley (Wasps).
:: Squad to be reduced to 22 on February 9.
Young players to train with England squad:
P Christophers (Leeds), H Ellis (Leicester), D Flatman (Bath), A Hazell (Gloucester), J Forrester (Gloucester), T Palmer (Leeds), D Scarbrough (Leeds), A Titterrell (Sale)