"Chris Bosh will not practice today and will not accompany the team to Atlanta for the game on Friday," the statement read. "When further information is available that we can pass along, it will be provided."
Bosh, 31, withdrew from the All-Star Game and 3-point contest. Due to his history of blood clots, any calf issue required follow-up tests because the calf is where many blood clots originate.
He was hospitalized for nine days during the 2015 All-Star break to treat blood clots that had traveled to his lung, as well as an infection that caused fluid to be backed up in his chest. Bosh was placed on blood thinners and missed the Heat's final 30 games of the season.
The clots were initially the result of a calf bruise he suffered in December 2014. Bosh said doctors told him at the time that he doesn't carry the genetic traits that would make him a likely candidate for a recurrence of clots. He endured six months of rehab before returning for training camp this season.
Bosh, in his 13th season, had said he was "optimistic" this latest calf strain wasn't serious but still planned on seeing a doctor on Monday in Miami.
The 11-time All-Star conferred regularly with Heat medical officials about the issue, which he has been dealing with and getting treatment for over the past several days. Bosh came to Toronto with hopes of participating in Saturday's 3-point contest and Sunday's All-Star Game, but he dropped out Friday out of concern of making the calf worse.
"I've been kind of down a little bit for the past couple of days," Bosh said Saturday in Toronto. "I just wanted to make sure I was taking the necessary precautions and being a good professional."
Bosh leads the Heat in scoring this season, averaging 19.1 points per game.