England head coach Stuart Lancaster has kept his options open for the Six Nations match against Ireland on Sunday by retaining both Billy Twelvetrees and Manu Tuilagi.

Lancaster has released seven players back to their clubs but also kept Gloucester's Ben Morgan in the squad for further treatment on an ankle injury.

Twelvetrees came in against Scotland for Mani Tuilagi and scored one of England's four tries on his debut cap but Lancaster is likely to start the more experienced Tuilagi against an Ireland team that is likely to include Brian O'Driscoll.

Leicester Tigers' No.8 Thomas Waldrom has also been retained by Lancaster so he could replace Morgan whilst the Gloucester forward is injured.

Alternatively Tom Wood could move to No.8 with James Haskell starting at blindside flank.

Lancaster has kept 25 players in the squad not including Morgan and released Mouritz Botha, Freddie Burns, Lee Dickson, Ben Foden, Will Fraser, Jonathan Joseph and Matt Kvesic back to their Premiership clubs.

England Senior training squad (25)

Chris Ashton (Saracens) , Brad Barritt (Saracens) , Mike Brown (Harlequins) , Danny Care (Harlequins) , Dan Cole (Leicester Tigers) , Owen Farrell (Saracens) , Toby Flood (Leicester Tigers) , Alex Goode (Saracens) , Dylan Hartley (Northampton Saints) , James Haskell (London Wasps) , Joe Launchbury (London Wasps) , Courtney Lawes (Northampton Saints) , Joe Marler (Harlequins) , Geoff Parling (Leicester Tigers) , Chris Robshaw (Harlequins) , David Strettle (Saracens) , Manusamoa Tuilagi (Leicester Tigers) , Billy Twelvetrees (Gloucester Rugby) , Billy Vunipola (London Wasps) , Mako Vunipola (Saracens) , Thomas Waldrom (Leicester Tigers) , David Wilson (Bath Rugby) , Tom Wood (Northampton Saints) , Ben Youngs (Leicester Tigers) , Tom Youngs (Leicester Tigers)