Pope Francis will not lead New Year’s Eve and New Year’s Day services because of a flare-up of his sciatica condition, which causes pain in his right leg, the Vatican said on Thursday.

It was believed to be the first time since he became pope in 2013 that Francis, who turned 84 this month, will have skipped leading a major papal event for health reasons.

A year-end vespers service that the pope was to lead on Thursday evening will be led by Cardinal Giovanni Battista Re, and the Friday Mass, marking the Catholic Church’s World Day of Peace, will be said by Cardinal Pietro Parolin, the Vatican secretary of state.

Both the vespers and the Mass require the main celebrant to stand for most of the service.

The pope will, however, lead his noon prayer on Friday as scheduled, the Vatican said.

Francis suffers from sciatica, a condition that causes pain that radiates from the lower back along the sciatic nerve to the lower part of the body. He is sometimes seen walking with difficulty because of the pain and receives physical therapy. Reuters