London Wasps and England winger Christian Wade and Brad Barritt have been called to Australia to join the British and Irish Lions squad as backline cover.
Wasps' wing Wade was due to start England's 2nd Test against Argentina in Buenos Aires on Saturday and was replaced by Jony May.
He will join up with the squad in Sydney on Monday morning and travel to Canberra.
There is concern over an injury to Wales's backs George North and Jamie Roberts and British and Irish Lions Head Coach Warren Gatland said, "We have obviously got ongoing treatment of some players so it's prudent to make sure we have enough backline cover."
"Christian played well in the 1st Test against Argentina and is match fit."
England Head Coach Stuart Lancaster said: "We're delighted for Christian. He's been in excellent form, played really well on his Test debut against Argentina last weekend and he goes with the best wishes of all the England players and management.
"Jonny May comes into the side to win his first cap against the Pumas today. He's been an important part of our squad over the last four weeks, he's up to speed with everything we're doing and this is a great opportunity for him."
Saracens' England centre will fly from the United States on Saturday evening and join the squad in Sydney on Monday before travelling to Canberra.