Cooper was given time off by his French club Toulon -- which made him a big-money marquee signing last year -- as he seeks to win a place at the Rio 2016 Olympics.
However, he has been omitted from Australia's squad for this weekend's Sydney Sevens because coach Andy Friend believed he was not ready to play.
"Quade is an exceptional footballer and has shown real character to put his hand up and say I want to be part of this team and work hard for this opportunity," Friend said Thursday.
"That's exactly what you want. There is no doubt in my mind that he will be a tremendous addition to the squad as we build towards Rio, but due to circumstances which were beyond Quade's control, and our control, he just couldn't get enough work in this week with the team."
The 27-year-old arrived in Australia on Wednesday and went straight to practice with his new teammates in their final full session ahead of the tournament.
"A lot of the boys didn't expect him to run but he really threw himself out there," fellow 15-a-side player Henry Speight, who is in the squad for this weekend's tournament, told the Sydney Morning Herald
"It just shows the character of the man running the first two laps with a praline bun in his hand -- basically his breakfast. Off the plane, straight into team meeting, straight onto the paddock -- just shows his keenness for the program, and the boys really respect that.
"He's got a very special skill set and is very suited to sevens ... his long passing game and his unpredictability. If he does play it will bring a new dimension to our attacking game."
Cooper is considered one of Australia's most gifted running backs in the 15-a-side game, but has lacked the consistency to retain a regular place in the Wallabies' lineup.
He was selected for the 2015 World Cup in England, though was only a fringe player behind first-choice flyhalf Bernard Foley and was not in the squad for Australia's final defeat against New Zealand.
He joined Toulon after the tournament, but the club's owner Mourad Boudjellal has not yet been impressed by Cooper or his other high-profile signings.
"For now, Cooper is not what I was hoping for. But we have to also give him time," Boudjellal told Quinze Mondial in January.
"Right now if I say that I'm not happy with our stars, it's only because we expect a lot."
The Australian national rugby website reported last month that Toulon gave permission for Cooper to play in Sydney plus the last two 2015-16 Sevens World Series events in Paris and London in May
. This week it quoted Friend as saying he might play in Las Vegas next month.
"Quade is going to get his opportunities during the series and we are really excited to have him here in our group and with us throughout this preparation," Friend said Thursday.
"He'll spend the weekend embedded with the squad as well, that contact (with the team) is a really important part of his learning process in a different version of the game."
After his return, having played a club match on Sunday, Cooper said
: "It's never a waste of a trip.
"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 told the Sydney Morning Herald he had been talking with friend and fellow union convert Sonny Bill Williams, who made his sevens debut in New Zealand's victory in Wellington last weekend.
"He said it was tough and he said he's still a rookie," Cooper said of the All Blacks star, with whom he has trained as a boxer.
"I watched a few of his games and saw how well he went in patches -- it's like anything, you learn as quick as you can and you adapt as fast as possible.
"There is still so much learning to do and I think for both myself and him it's very similar to boxing. When we started boxing we knew very little, and still do, but we put ourselves in that position to learn and that is where the challenge comes -- in just being able to learn on the run."
Cooper was expected to be one of the star attractions in Sydney, which this year takes over from the Gold Coast as Australia's host venue.
Australia, which has not won its home tournament since 2002, will play trans-Tasman rival New Zealand in its final group match on Saturday.