Following a consultation with specialists on Tuesday and an MRI scan after the RBS 6 Nations win over France, medical staff are yet to find a conclusive explanation for the problem.

But Warburton is hoping a visit to a specialist in London to determine the extent of the injury caused by a collision with France hooker William Servat.

"All the scan showed was that there was no soft tissue damage, but they don't know if it's maybe a more complicated, underlying factor, which could be a number of things,” Warburton said.

"It could be something to do with nerves, which don't show up on MRI scans.

"There has been some improvement since the weekend. However, it's hard to tell how much. It's still painful.

"I do not know what to think and that is why I am seeing the specialist. It could be two weeks or it could be two months: I just hope it is shorter rather than longer. One of the reasons they are finding it difficult to assess the injury is that I cannot remember when it happened.

“I remember competing at a ruck and Williams Servat running in head first but I get stingers in games all the time. They last five minutes but wear off. I felt the bang but there was no obvious pain. It was a few minutes afterwards when it started to hurt."

A series of niggles limited Warburton to only 240 minutes of a possible 400 in the RBS 6 Nations.

And he revealed that he asked teammates Gethin Jenkins and Ryan Jones to lift the RBS 6 Nations trophy having missed games against Scotland and Italy,

“I have been nursed in training throughout the campaign because I had been injured and I felt that because they had had more game time than me and put themselves about more, they deserved it more than me.”