Playmaker Quade Cooper trained with the Australian Sevens for the first time on Wednesday, but it is unclear whether he will feature in this weekend's Sydney 7s.
Cooper arrived back in Australia on Wednesday morning, after playing for Toulon against Stade Francais on Monday morning (AEDT), and headed straight to training.
New Australian Sevens head coach Andy Friend said a post-training medical would likely determine Cooper's availability.
"He's just had his first run so we'll get the medical staff to assess him after this and then we'll make a decision," he said.
Cooper said he wasn't sure whether he would be ready for Sydney, given the different demands of Sevens.
"With 15s, you know how hard you need to go for that first 10 and then you when to pull back and settle into the game," he said.
"With Sevens, I'm not entirely sure how to do that so that's the big part where I'm nervous."
If Cooper does not play in Sydney, Friend said the 27-year-old would likely feature in the Las Vegas leg at the end of March
Regardless of whether he plays, Cooper said he felt the trip back to Australia would be worth it.
"It's never a waste of a trip," he said
"The biggest thing with a team sport is to fit in with the team culture I'm glad to be here to have the opportunity to train."
Cooper’s Wallabies teammate Henry Speight is likely to line up in Sydney, in his second World Series outing.
Sevens regulars, including captain Ed Jenkins and Cam Clark are expected to return for the tournament after missing the Wellington leg.
The Australian Sevens trained on Wednesday morning in their last full session before the Sydney 7s, with a captain’s run scheduled for Friday.
The team is set to be announced on Thursday.