Lombardi said he didn't expect the pope to be given any other duty, given his age, and he said Benedict would no longer be involved in decision making or administrative duties.
Pope Benedict was "very discreet" and was "not someone who will interfere" or create issues in terms of his successor, he said.
Where will the former pope live?
After he steps down, Benedict will move to the pope's summer residence, Castel Gandolfo.
At a later date he will move into in a monastery at the Vatican.
The monastery has recently been renovated and extended to include a small chapel.
What will Pope Benedict be known as once he has stepped down as pope?
According to the Catholic Bishops' Conference of England and Wales, Pope Benedict will return to being known as Cardinal Joseph Ratzinger. It said he would be addressed as his eminence or Cardinal Ratzinger.
However, Lombardi later told reporters it was hard to imagine that the pope would be called a cardinal.