The Sydney Roosters insist Luke Keary will be fully fit for Saturday's NRL preliminary final against North Queensland, with the playmaker resuming training after a bout of food poisoning.

Keary returned to light duties on Tuesday after being quarantined from the squad for two days running.

Skipper Boyd Cordner said the five-eighth was in no doubt for the grand-final qualifier at Allianz Stadium.

"He's fine. Yesterday, (he) was feeling a bit crook, wasn't feeling great and went home," Cordner said.

"He just went home just to get right. We've still got a bit of time before we get to game day. We want him right for all the big (team) sessions.

"But he was in today, doing some stuff. He's fine -no dramas; no worries."

The Roosters will have Wednesday off before returning to the training paddock on Thursday and completing their preparations on Friday.

Cordner said Keary and NSW State of Origin half Mitchell Pearce had a strong enough partnership to work through the setback.

"He's been there all year for us," Cordner said.

The 25-year-old Keary has been a revelation since joining the Roosters this season, having played every game while leading the NRL for line-break assists with 31.

"He's a tough little bugger so he will be sweet," Pearce said.

If the Roosters beat the Cowboys on Saturday night, Keary will line up in his second grand final in four years after moving from South Sydney at the end of last year.