Bath prop Nathan Catt has been added the England tour party flying to New Zealand amid concerns over Mako Vunipola's knee injury.
Vunipola is being assessed ahead of Saracens' clash with Northampton in Saturday's Aviva Premiership Final.
Uncapped 26-year-old Catt has been promoted from the England XV squad that will face the Barbarians at Twickenham Stadium on Sunday and will fly out with the England squad on Tuesday.
"In light of Mako Vunipola's ongoing treatment for a knee injury ahead of the Aviva Premiership final and Joe Marler suffering a slight hip strain we have decided to take Nathan out with us now to ensure that he is up to speed with our systems and structures in the lead up to next week," said England Head Coach Stuart Lancaster.
Leicester Tigers prop Fraser Balmain will replace Catt in the England XV squad to prepare for the game against the Barbarians.