Flyhalf Owen Farrell will lead England in the Six Nations in the absence of injured hooker Dylan Hartley, while scrumhalf Danny Care has also missed out on the 35-man squad.
Hartley, who was co-captain along with Farrell during the November Tests, has failed to recover fully from a knee injury.
In some good news for England, experienced trio Mako and Billy Vunipola and Joe Launchbury are back in the squad, having recovered from their respective injuries.
Care, who has 84 Test caps, is the most notable omission, with Dan Robson handed a late chance to press his claims for World Cup selection.
England coach Eddie Jones has named four uncapped players in the squad – Gloucester wing Ollie Thorley, Saracens loose forward Ben Earl, Wasps scrumhalf Dan Robson and Worcester hooker Jack Singleton.
‘We are very happy with the squad and have a number of players who have come back from long-term injury,’ said Jones. ‘We are looking forward to getting across to Portugal and having a good 10-day preparation for the Ireland game [in Dublin on 2 February].
‘The first thing when we get together as a squad is to get our cohesion back. The players have been playing for their clubs with different styles and different playing philosophies, so it’s about getting them thinking about playing the England way. The second thing is to get our togetherness stronger to work as hard as we can to make sure we are well connected on and off the field, so Portugal is an important camp for us.
‘Ireland is the best side in the world. They are a very well coached and drilled side and have particular things they do well in the game. To beat Ireland, we need to compete brutally in all the contest areas of the game.’
‘Unfortunately, Dylan won’t be available for the Ireland game so we won’t take him to Portugal, but we are hopeful he will be back later in the Championship. Owen will be captain by himself and he will certainly have great support from a number of senior players.’
Forwards: Jack Clifford, Dan Cole, Luke Cowan-Dickie, Tom Curry, Ben Earl, Ellis Genge, Jamie George, Nathan Hughes, Maro Itoje, George Kruis, Joe Launchbury, Courtney Lawes, Ben Moon, Brad Shields, Kyle Sinckler, Jack Singleton, Billy Vunipola, Mako Vunipola, Harry Williams, Mark Wilson.
Backs: Chris Ashton, Mike Brown, Joe Cokanasiga, Elliot Daly, Ollie Devoto, Owen Farrell (c), George Ford, Jonny May, Jack Nowell, Dan Robson, Henry Slade, Ben Te’o, Ollie Thorley, Manu Tuilagi, Ben Youngs.
Photo: Ashley Western/Getty Images