England lock Nick Kennedy has dropped out of the Test squad for the series against Argentina and will continue his recovery from knee ligament damage with the Saxons.
Kennedy suffered the injury in London Irish's Guinness Premiership semi-final victory over Harlequins and will not be fit in time to feature in either of England's Tests against the Pumas.
But the England management are hopeful that Kennedy could be available for the latter stages of the Churchill Cup, which run from June 6-21 in Denver.
Saxons head coach Stuart Lancaster has made three other changes to his squad ahead of their departure this afternoon.
Alex Corbisiero (knee) and Alex Goode (ankle) have both dropped out injured while Matt Banahan has been promoted to the senior squad as a replacement for the unwell David Strettle.
Harlequins prop Mark Lambert replaces Corbisiero and Leicester winger Matt Smith comes in for Banahan (Bath Rugby) while Sale hooker Neil Briggs has been added to the squad as cover because Joe Ward has a calf injury.
Wales flanker Sam Warburton admits he will be proud to lead his country out for a record 34th time this weekend and hopes to cap the day off with a memorable RBS 6 Nations victory against in-form Ireland.