The Paris Saint-Germain striker resumed team training on Thursday following a hamstring injury he suffered in the 2-1 last-16 win over Portugal.
Cavani's return to the practice pitches at Uruguay's team base in Borsky came as a huge boost to Tabarez's plans for the clash with France at Nizhny Novgorod Stadium.
However, the 71-year-old was left frustrated by some of the media coverage of his forward's injury and recovery, so therefore said he will not disclose his team.
"From the moment he got this injury, it made him very sad," Tabarez told a news conference about Cavani. "He's a very important player for us and has been working very hard to recover. He's concentrating on his hopes and dreams.
— Edi Cavani Official (@ECavaniOfficial) June 30, 2018
"I think we've given enough information about Cavani's injury: we said what happened, we informed everyone with two press releases. There were many rumours so we issued a second release to explain exactly what kind of tests he had, and nobody respected it, so people started asking other professionals, who aren't here.
"I've already said enough about Cavani. In less than 24 hours, you'll know who will play. We're not trying to pretend. We're not trying to create any doubts or rumours."
Tabarez was keen to praise Cavani for his attitude in training, though, and thinks the camaraderie in the squad between the senior stars and younger players will stand Uruguay in good stead as they bid to reach the semi-finals.
"I'm always happy to see how, for instance, Cavani trained today [Thursday] with his team-mates and to see how they joked around is very positive," he said.
"That's what happens when you have a family or group of friends together. If they're confident and happy then it's more likely they will make the right decision on the pitch.
"We have a plan like any team and you have to implement that on the pitch. It's a strength that we are a close team and that's not something the opposition can take from us."
Photo Getty Images. Caption: Edinson Cavani returned to Uruguay training on Thursday