Davao City Vice Mayor Sebastian "Baste" Duterte said Tuesday he withdrew his candidacy for reelection but gave no reason for the move.
The youngest son of President Rodrigo Duterte named lawyer Melchor Quitain Jr. as his substitute.
"I am deeply grateful to the Dabawenyos for the support they have given me all this time. I have no other details to share at the moment," the younger Duterte said in a statement.
His elder sister, Davao City Mayor Sara Duterte-Carpio, is seeking reelection in their hometown despite calls for her to run for president.
PDP-Laban standard-bearer Sen. Ronald "Bato" dela Rosa earlier said that he was open to being substituted by Duterte-Carpio, who has until Nov. 15 to decide.
Duterte-Carpio has also dismissed talks that she would run for vice president alongside presidential aspirant Bongbong Marcos, the only son and namesake of late dictator Ferdinand Marcos Sr.