Yahoo Sports and the Miami Herald reported Monday night that Bosh will be examined Thursday when he returns to Miami. Bosh was in Toronto for the All-Star weekend before he was replaced on the East team Friday.
According to both reports, Bosh's condition isn't life-threatening, but the team will determine whether the use of blood thinners will be required.
The Herald asked Bosh's agent, Henry Thomas, if his client was diagnosed with blood clots in his calf, and the agent replied via text, "Too soon for all of that. ... Too soon to report that."
Last season, Bosh missed the final 30 games due to blood clots that moved to his lungs from an earlier calf injury. He had sat out eight games due to the leg ailment before returning to play 21 games ahead of being shut down because of the lung issue.
According to the Herald, Bosh said last year that if blood clots ever returned, he would need to take blood thinners for the rest of his life.
Bosh, 31, is averaging 19.1 points and 7.4 rebounds per game this season. An 11-time All-Star, he won NBA championships with the Heat in 2012 and 2013.