Sydney Roosters prop Martin Kennedy will be provisionally suspended from the NRL on Friday morning over drug allegations made against him.

Kennedy has been given until mid morning to voluntarily stand down, before a later date with the NRL anti-doping tribunal.

The 26-year-old had been given until Thursday afternoon to reply, but that time frame was extended by 12 hours.

If Kennedy decides not to opt to stand down, the NRL is likely to suspend him from playing and training with the Sydney Roosters.

The NRL alleged in a statement on Wednesday the former Brisbane forward had breached the game’s anti-doping policy “through the possession and attempted use of banned substances.”

If found guilty Kennedy faces a two-year ban from rugby league under the WADA and ASADA codes, to which the NRL is a signatory.

It is understood Kennedy will challenge the allegations.