VIDEO: No World Cup guarantee for England stars
"Some may struggle to participate in the future," Jones said.
"There are some guys who are starting their international careers and they need time. I have to decide whether I have time to get them ready for the World Cup.
"We weren't happy being the team we were because we knew whatever we had won, we weren’t good enough to get to where we wanted to get.
"We knew we had to change and sometimes that hurts. It's not nice but it is part of the process of being a better team.
Despite the disappointing fifth-place finish, Jones is making sure he draws all of the positives he can from the tournament.
"You never find out about yourself unless you have these runs. When you take over it is quite easy to improve because you can fix things quickly. But internal mechanisms take time to fix. Unless you fix them they catch up with you when you get to the big tournaments, such as the World Cup. So for us it has been an enormously beneficial tournament, if disappointing."
England won't play again until late May, when they take on the Barbarians.
