Pope John Paul II (search), back from the hospital but still frail, sent a message of support to the sick Friday, saying he feels especially close with them and asking for their prayers.

The pope's letter was read at Mass at St. Peter's Basilica for the Church's World Day of the Sick (search). Before falling ill with the flu and breathing problems last week, the pontiff had planned to attend.

The 84-year-old pope sent out greetings especially to the ailing, "with whom I feel particularly close," said the message, which was read by Cardinal Camillo Ruini, the pope's vicar for Rome. The congregation broke into applause afterward.

"Your suffering is never useless, dear sick ones," the pope's message said. Pain is precious, he said, because it has a mysterious link to Christ's trial on the cross.

"For that reason the pope counts deeply on the importance of your prayers and your suffering," the message said. "Offer them up to the church and to the world, offer them also for me and for my mission as universal shepherd of the Christian people."

Many hoped the pope would show up. Ruini said he was following the service on television.

The pontiff spent his first full day back at the Vatican on Friday after overcoming breathing problems that required emergency hospitalization and left many wondering how he would continue in his papacy with such weak health.

The Vatican's official newspaper, L'Osservatore Romano, responded to any questions about whether the pope planned to resign with a banner headline: "The rudder is still in his hands."

Since the pope's appearance Sunday from his hospital room window, some have worried about his future at the head of the Church because his very brief words were almost entirely inaudible.

On Monday, Cardinal Angelo Sodano, who as secretary of state is the Vatican's No. 2, said the hypothesis of a papal resignation should be left "up to the pope's conscience."

No pope has resigned for centuries, and John Paul repeatedly has said he intends to carry out his mission until the end.

On Thursday, parents hoisted children on their shoulders to watch and Romans let out hearty cries of "Viva il papa!" — "Long live the pope!" — as John Paul, in his white popemobile, left the hospital.

In contrast to the hurried, late-night ride Feb. 1 to the Gemelli Polyclinic (search) in an unmarked ambulance as he lay in the throes of a breathing crisis, John Paul was brought home in full public view in his signature vehicle with see-through glass sides during the 10-minute drive, which was broadcast live on Italian TV. John Paul looked weary but occasionally raised his right hand in greeting.

The Vatican took pains to make the pope as visible as possible amid questions about whether he can continue to head the church while Parkinson's disease (search) continues to exact its toll on his health, his mobility and ability to speak.

Papal spokesman Joaquin Navarro-Valls said John Paul had recovered completely from the breathing crisis, which developed while he was down with the flu. A battery of tests ruled out any new illnesses, the spokesman said.

Private Lenten spiritual exercises are slated to last from Sunday evening until Feb. 19, when, according to a Vatican schedule published before John Paul's hospitalization, the pontiff is to preside at a Mass in St. Peter's Basilica.

"When he gets back to the Vatican he will look over, and decide with his doctors, what his appointments will be," Navarro-Valls said.

Many will be watching Sunday to see if John Paul keeps his customary noon appearance at his studio window on St. Peter's Square.