I think he won't travel that much anymore, because it's more and more of an effort," Rev Georg Ratzinger said of Pope Benedict XVI, who has looked frail in recent weeks.
Rev Ratzinger, who is three years older than his brother, made the remarks during an interview with a Catholic news agency in Germany, KNA.
The Pope, who turns 85 on April 16, looked tired during Easter services in Rome.
His duties included leading the annual Way of the Cross procession around the Colosseum on Good Friday and celebrating Mass on Sunday in St Peter's Basilica.
Pope Benedict XVI to cut back on foreign trips - Telegraph