England's Mako Vunipola has not been named in the 33-man squad for their third Six Nations match against Ireland on Sunday after the prop travelled back to Tonga for family reasons, the Rugby Football Union (RFU) said on Tuesday.
Vunipola, 29, did not play a part in their shock opening defeat by France earlier this month but started the second match when they beat Scotland in Edinburgh.
Beno Obano joins Joe Marler and Ellis Genge as the three loosehead props named in Eddie Jones' group on Tuesday, which will be trimmed to a matchday 23 on Friday.
Centres Manu Tuilagi, who injured his groin in the first game, and Henry Slade who has been out since December with an ankle injury, have both recovered and were named in the squad. They filled the midfield, with Owen Farrell at flyhalf, in last year's victory in Dublin, one of England's best Six Nations performances for many years.
Northampton Saints' scrumhalf Alex Mitchell was also named as an apprentice player.
England are fourth in the standings with five points while Ireland are second with nine points ahead of the match at Twickenham.
Luke Cowan-Dickie (Exeter Chiefs), Tom Curry (Sale Sharks), Tom Dunn (Bath Rugby), Ben Earl (Saracens), Charlie Ewels (Bath Rugby), Ellis Genge (Leicester Tigers), Jamie George (Saracens), Maro Itoje (Saracens), George Kruis (Saracens), Joe Launchbury (Wasps), Courtney Lawes (Northampton Saints), Lewis Ludlam (Northampton Saints), Joe Marler (Harlequins), Beno Obano (Bath Rugby), Kyle Sinckler (Harlequins), Will Stuart (Bath Rugby), Sam Underhill (Bath Rugby), Harry Williams (Exeter Chiefs)
Elliot Daly (Saracens), Ollie Devoto (Exeter Chiefs), Fraser Dingwall (Northampton Saints), Owen Farrell (Saracens), George Ford (Leicester Tigers), George Furbank (Northampton Saints), Willi Heinz (Gloucester Rugby), Jonathan Joseph (Bath Rugby), Jonny May (Leicester Tigers), Henry Slade (Exeter Chiefs), Ollie Thorley (Gloucester Rugby), Manu Tuilagi (Leicester Tigers), Jacob Umaga (Wasps), Ben Youngs (Leicester Tigers) (Reporting by Rohith Nair in Bengaluru; Editing by Hugh Lawson)