Popovic said he would make a call on whether to include the attacking midfielder in his squad, for the game at Pirtek Stadium, after the team's final training session on Wednesday.
"We'll have to see, because we're training quite hard and trying to get Dario up to speed," Popovic said.
"He trained today and once we have a look at him at training tomorrow we'll decide.
"We've got to look at the first-up game, which is important, but we've also got to look after the player as well and make sure we get a full season out of him."
Vidosic, capped 23 times for Australia, has only been with the Wanderers for two weeks and has just 15 minutes of match experience with the team so far - during extra-time in its FFA Cup quarter-final against Perth Glory.
The only reason he got on the field at all in that match was because Brendon Santalab was a late withdrawal after being injured in the warm-up.
Vidosic had travelled to Perth to continue training with the team with an eye to the A-League campaign, in which Popovic said he would feature heavily.
"I think we all know what a talent he is and he's at a fantastic age (28) for us as well," Popovic said.
"He's a very creative player, but he needs a bit of time to settle in.
"He hasn't played a lot of football recently, but with each training session he's getting better and better. I think he'll be a very good player for us this year."
Vidosic said he was doing his bit at training and hoping it would be enough to get him into the squad against Roar.
"It was good to get the 15 minutes against Perth, which was unexpected," Vidosic said.
"We don't want to see any of our boys get injured, but it was still good to make a debut and have that 15 minutes in the legs.
"I think by that stage of the game everyone was feeling tired, so the tempo was good for me to get that initial feeling.
"I've trained very hard this week and they've had the GPS on all of us, they've had heart rates on all of us and that will be the best indication of how I compare with the rest, because I've come in at a later time and I'm still learning my part.
"I want to play, but whatever the decision is from the coach, I'll respect it. The most important thing for me is to be patient. That's the clearest word in my head - patience.
"The coaching staff are the experts and they know what's right for the team and for me. I'd love to play on Thursday, but I'll wait for them to give me the nod and once the day comes I'll be ready - whenever it is."
Vidosic said it wasn't just about conditioning for him at training, but also learning the Wanderers playing style and how to best fit into it.
"Every day I come in and push myself as hard as I can and make sure I get the most out of the session," he said.
"I'm trying to catch up on everything I've missed by not being here at the start of the pre-season.
"It's not just the fitness, but the way the team wants to play. I've got to be patient and everyone needs to have that patience with me as well.
"What I bring to the team I'll need to adjust to exactly what the team wants to do, so it's all part of a learning curve where I try to soak in as much as possible - even if I have to annoy the coaches, pull them aside and ask them to show me everything that needs to be learned.
"I'm willing and I want to learn quickly. I just want to play football, so I'm trying to get up to speed ASAP."