A court has heard emerging NRL star Tristan Sailor allegedly drugged a woman before assaulting her.

The son of Wendell Sailor was granted bail on Sunday after being arrested on Saturday and charged for allegedly assaulting a woman in Sydney last weekend.

Police prosecutor Shannon Ryan told the court toxicology reports had detected a sedative in the alleged victim's bloodstream.

Ryan described Mr Sailor's alleged actions as โ€œpredatory and plannedโ€.

Sailor was arrested by NSW police on Saturday after they raided his home that he shares with his parents.

Police received a complaint from a 24-year-old woman that she was sexually assaulted last weekend.

Sailor made five appearances for the Dragons between 2019-2020 but has not been offered a spot on their 2021 list.