The England captain was knocked out in the Grand Slam game against France and has played only 17 minutes since ahead of tomorrow's Test against Wales at Twickenham.

That was not the first time the hooker had to observe the concussion protocol - he spent six weeks on the side-lines at the turn of the year after a collision with Billy Vunipola in a club match for Northampton.

He struggled with lethargy and his partner Jo, the mother of his daughter Thea, saw it at first hand.

"My missus is closest to me and sees me every day, so when I wasn't right she knew it and when I got better she knew that I was okay. There's no lying," said Hartley.

"If I got another one now I would be worried. I would probably start looking at other careers or stuff like that, or maybe a long lay-off. Maybe I look at my tackling technique too.