LONDON - Dylan Hartley will captain England in Saturday's third test against South Africa in Port Elizabeth after Chris Robshaw was ruled out with a cracked bone in his right thumb, the RFU said on Monday.
Robshaw suffered the injury in the first test but it was only revealed in a scan after he took another knock at the weekend.
"I'm absolutely gutted," he said in a statement. "I've been very proud and honoured to lead this group during the Six Nations and on this tour and it's a difficult way to end the season."
Head coach Stuart Lancaster said medical advice was that Robshaw should not play.
"Dylan Hartley will captain the side. He has been a key part of our leadership group and I know he will step up to the task on Saturday," he added.
South Africa clinched the three-test series after defeating England 36-27 at Ellis Park in Johannesburg in the second test on Saturday.
England will also be without scrumhalf Ben Youngs due to a shoulder injury.