Ahead of the Autumn Internationals with Samoa, South Africa, New Zealand and Australia, Lancaster has insisted that there is still time for players to force their way into his plans as England prepare to host the tournament next year.
"It's a really exciting time for English rugby, we have such a good young, talented team coming through," Lancaster told Sky Sports News.
"I am 80% there, but the camp will be competitive and so it should be as it is a once in a lifetime opportunity.
"The pain of losing certainly drives us. It's quite a good thing to have it sit inside us."
Lancaster meet New Zealand at Twickenham on November 8.