The 35-year-old Wasps number eight has reiterated that he will not retire from international rugby but acknowledges the decision may be made for him.
"I'm not about to make any decisions on England either way," he said.
"You're invited to play for your country - not the other way round.
"But, if you're an England coach, now you start to look to the future don't you? If someone is 35, he's not really the future.
"There are many good players coming through now and I think they will get the opportunity that perhaps they haven't had over the last two or three years."