The pair have been left out of the Blues' starting line-up for the Carling Cup clash with Bolton on Wednesday, with Terry given the night off altogether.
Many believe England's chances at past major tournaments have been hampered by gruelling fixture schedules, with many fatigued before the tournament has even begun.
Ancelotti has vowed to rest his international players any chance he gets, with Lampard playing 57 times in all competitions last term and Terry closely following him on 51.
"If I have a possibility to give rest to the players, above all those who play in their national teams, it's better," he said.
"At this moment, Terry and Nicolas Anelka are in very good condition, but if we want to maintain that, it's better to give them a rest.
"They do want to play every game, even this season. But for them it's better sometimes to rest.
"It's very important to prevent injuries. When I played, it was work, work, work every day. These days you work hard with intensity, but it's also important to give the players rest to prevent injuries. This is our way.
"We used this in Milan and we're using it now at Chelsea. When I arrived here I found a very good situation here already. Chelsea have been doing that.
"I think at the end of May, Terry and Lampard will be in very good condition and will do a fantastic World Cup.
"He (Lampard) is not disappointed. He realises it's important for him to give his body some recovery time. He's not a young player. You have to maintain a good control."