England skipper Dylan Hartley has confessed that another layoff through concussion would likely be enough to make him consider his future.
The 30-year-old has missed a total of 14 weeks this season, across two separate spells, because of head-related injuries.
Hartley was most recently knocked out in the final match of England's Grand Slam-winning campaign in March, and only made his return to action in club side Northampton Saints' final match of the season earlier this month.
Sunday's international Test meeting with Wales at Twickenham will be just Hartley's second outing of his comeback, providing a chance to improve his fitness levels.
"If I got another layoff now, I'd be worried. I'd probably start looking at other careers or maybe a long layoff," he is quoted as saying by Sky Sports News. "Maybe I'll look at my tackling technique too.
"I'd have to ask a specialist. 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."
Hartley will be among the starters for England at Twickenham in a squad that includes four uncapped players.
