|England v Wales|
|Venue: Twickenham Date: Sunday, 29 May Kick-off: 15:00 BST|
|Coverage: Live on BBC Radio Wales, Radio 5 live, BBC Radio Cymru, the BBC Sport app, Connected TV, and live text commentary on the BBC Sport website. Highlights on BBC Two at 19:00 BST.|
England captain Dylan Hartley has said that one more concussion would make him consider his future in rugby.
The 30-year-old Northampton Saints hooker has missed 14 weeks this season because of head injuries.
Hartley, who returned to action this month after being knocked unconscious during the Six Nations in March, will lead England against Wales at Twickenham on Sunday.
He said: "If I got another lay-off now, I'd be worried."
The New Zealand-born front-rower continued: "I'd probably start looking at other careers or maybe a long lay-off. Maybe I'll look at my tackling technique too.
"Three in one season would warrant a bit of time off and I would probably take that anyway - take a step back and have a minute.
"It's not something I fear. It's something you deal with when it happens. I won't go into the Wales game worrying about it.
"I feel confident in my head and have tested it out a few times."
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Hartley, who has 71 caps, previously admitted he had no recollection of lifting the Six Nations trophy following his blow to the head in the Grand Slam-winning victory over France.
He was eventually passed fit to play in time for Northampton's last Premiership game of the season against Gloucester on 7 May.
But Hartley, who was made England captain in January by new head coach Eddie Jones, admitted he struggled with day-to-day life while he waited to begin the return-to-play protocols.
"I couldn't run or do anything and spent a lot of time on the couch," he said. "It was lethargy, constantly wanting to sleep.
"I had no urge to get on the [indoor] bike. I almost tried forcing myself to get on and I just said 'I can't be bothered', so I went back to lie on the couch and went to sleep.
"There's no lying in your recovery. I had a constant reminder of that every time you see your kid and you think 'if I hit my head again, what's that going to mean?'.
"Then I just turned the corner one week and it was great to get that run-out against Gloucester for a bit of confidence."