Isi Naisarani has had to work for his Rebels return after failing to hit fitness targets in his comeback from injury.
Naisarani will start for Melbourne this weekend against the Force in his first Super Rugby AU outing, and 50th Super Rugby cap, after battling a hamstring injury.
The 25-year-old suffered the injury during isolation training but it was his slow return to full fitness after the injury that has held him back in recent weeks.
Wessels said there were simple fitness benchmarks Naisarani had to meet before returning to the matchday 23.
"Isi has taken longer to come back, he probably wasn't in the condition that we needed him to be in to get back," he said.
"I think those standards should apply to Wallaby players as much as they apply to anybody else.
"He wasn't quite ready, he's now done the work and he's ready to play.
"Almost every training session this week, he's played like a World Cup final, he's absolutely raring to go.
"He's going to be firing on all cylinders and very excited to have him back."
Naisarani has been one of the Rebels stars in his two seasons with the club but Wessels said he couldn't bend his rules for anyone.
"He got injured working during lockdown so to his credit he was actually doing some high speed running training during lockdown and unfortunately he did a hamstring injury which had some tendon involved which was quite a significant injury but then he's been slow to get back to his fighting weight," he said.
"We set some markers for everybody in the squad and it doesn't matter who you are, you don't have the markers, you're not eligible for selection. To his credit, that wasn't easy for Isi if you're not in full team training.
"That's also difficult and you're on tour, you've got the buffet meals every night and I think to Isi's credit, he's really worked hard over the past couple of weeks to get to his fighting weight."
Wallabies coach Dave Rennie has spoken about his desire to improve fitness of players around the country as a priority.
Wessels said, generally speaking, he was pleased with his own team's fitness.
"We've come out of the COVID break and we had 16 guys run personal bests on their fitness scores having been away in isolation," he said.
"We're really proud of that and it probably talks to the emphasis that we put in on that preparation.
"That's a big part of the way we play so it's the way that we train.
"I can't talk for the other teams in terms of what Dave Rennie said but I'm certainly happy with where our group's at."
The Rebels will be without skipper Dane Haylett-Petty for up to six weeks after he suffered a medial ligament injury against the Waratahs last weekend.
Wessels was confident the fullback would be back in action before the end of Super Rugby AU, with medical staff positive about Haylett-Petty's prognosis.
In positive news, Brad Wilkin returns to the bench after more than a year out with an ACL injury.