Co-captain Dylan Hartley has been left out of England's training squad for their Six Nations opener against Ireland as the hooker battles a knee injury.
Owen Farrell will therefore skipper the team, while head coach Eddie Jones has included four uncapped players in a 35-man party - OIlie Thorley, Dan Robson, Jack Singleton and Ben Earl.
England are boosted by the return of Billy Vunipola, Joe Launchbury, Mako Vunipola and Ellis Genge for the first time since last year's tour of South Africa, while Dan Cole, Jack Clifford and Ollie Devoto are also included after long absences.
"Unfortunately, Dylan won’t be available for the Ireland game so we won't take him to Portugal [for a training camp] but we are hopeful he will be back later in the championship," explained Jones.
"Owen will be captain by himself and he will certainly have great support from a number of senior players."
England open their campaign in Dublin on February 2 against an Ireland side who completed the Grand Slam at Twickenham last year.
"Ireland are the best side in the world," Jones added. "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.
"We are very happy with the squad and have a number of players who have come back from long-term injury.
"We are looking forward to getting across to Portugal and having a good 10-day preparation for the Ireland game."
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 (captain), George Ford, Jonny May, Jack Nowell, Dan Robson, Henry Slade, Ben Te'o, Ollie Thorley, Manu Tuilagi, Ben Youngs.