Pacquiao has traditionally visited a central Manila cathedral on the day he returns to the Philippines from a fight abroad, but it is not yet known if he will continue this practice amid fears over the potential spread of A(H1N1).

Crowds hoping to see Pacquiao were gathering Friday at the church, normally one of the busiest in the country.

Health authorities, acting on World Health Organization advice, had appealed to Pacquiao on Wednesday to quarantine himself and delay his flight by five days to allow time for the boxer and his large entourage to be given the all-clear.

But the six-time world champion -- widely considered the sport's best pound-for-pound fighter -- had insisted on flying home from the United States as scheduled on Friday.

The "Pac Man" has been told that President Gloria Arroyo, who has pledged a city-wide parade and a national holiday to celebrate his victory, would not give him an audience at the presidential palace before next week.

The main concern was the prospect of Pacquiao or his entourage infecting large numbers of people during the planned parade.

Pacquiao won Hatton's IBO light-welterweight title in spectacular fashion at the weekend, knocking his opponent out inside two rounds.