Green, 31, initially made himself unavailable for today's match but was persuaded to return following the birth of his child and because back-up keeper David Stockdale was absent getting wed yesterday.
Manchester City ace Hart, 24, will earn only his 11th cap against the Swiss at Wembley today.
And Capello said: "Green didn't play because Hart needed more international games. For this reason, Green hasn't played a lot since South Africa but Green is a really good player. For the young players, like Hart, they need more international games."
Capello also claimed Birmingham's Ben Foster has only quit England temporarily and not retired.
He said: "The problem with Foster is his finger. He told us: 'I need to have an operation'."