NSW fullback James Tedesco will give himself until Saturday to prove his fitness to play in the opening State of Origin clash in Adelaide next week.

The 27-year-old is suffering from a grade-two medial ligament injury and began straight line running for the first time since shedding the knee brace at Blues training on Tuesday.

He was also put through acceleration and deceleration tests and said he felt fine afterwards.

Heavily strapped during the drills, it was Tedesco’s first real test of the knee he injured in the Sydney Roosters’ semi-finals loss to Canberra.

And with a brutal three-week series to start next Wednesday night, the Blues would be reluctant to risk their star fullback if he’s not right.

“I’m doing everything I can for game one, so first day was just to get running and get through it, it felt pretty good,” he said on Tuesday.

“Next training is Thursday so we progress and do a bit more volume and changing direction.

“It’s more just how it feels at the moment.

“In my head I feel pretty clear and I feel pretty confident in it, so that’s the main thing.”

Saturday’s session will be a full hit out and Tedesco wants to get through most of it before making a call.

It will come after the 21-man team for game one is named on Thursday.

Parramatta fullback Clint Gutherson was running at fullback on Tuesday’s session, while Clive Churchill Medallist Ryan Papenhuyzen will join the squad in camp on Wednesday night.

Both are capable replacements.

“Either of those guys could do a good job for us, they’ve both had really good years. Gutho can play anywhere as well,” Tedesco said.

“(Papenhuyzen) killed it.

“He had a really good year and obviously during the semis and in the grand final he was their best player.

“I spent a bit of time with him at the Tigers so it will be good for him to come in and talk about footy and try and teach him a few things as well.

“It’ll be good to have him in camp.”

Meanwhile, Roosters five-eighth Luke Keary made it clear he is ready if picked to make his Origin debut for the Blues next week.

There were doubts about his fitness after he copped a head knock in their final game against the Raiders.

However, he quickly snuffed them out on Tuesday.

“My brain is fine so everyone can stop stressing,” he said.