ROME — Pope Francis decided at the last minute to skip his homily during Palm Sunday Mass in St. Peter’s Square, avoiding a strenuous speech at the start of a busy Holy Week that will test his increasingly frail health.

Hobbled by bad knees and persistent respiratory problems, Francis also didn’t participate in the procession of cardinals around the obelisk in the piazza at the start of the Mass. Instead, the 87-year-old pontiff blessed the palm fronds and olive branches carried by the faithful from the altar.

Francis had been expected to deliver a homily halfway through the service and had pronounced the prayers during the Mass. But after several seconds of silence, announcers said Francis had decided not to deliver the homily itself.