TB12 got in the sweat sesh with about two dozen Tampa Bay players down at Berkeley Preparatory School in Florida for around two hours ... according to the Tampa Bay Times.

And, as you can see in a pic from the workout, TB12 was all smiles ... even though some of his new squadmates (presumably the ones NOT at the workout) have recently contracted coronavirus.

Over the past week, the Bucs confirmed several players and coaches tested positive for COVID-19 ... and the NFL warned teams to be careful about going through private workouts amid recent surges in positive cases.

Unclear what social distancing steps Brady and the Bucs took to limit possible exposure at their Tuesday practice ... but what we do know is Tom is at least very aware of the pandemic.

Remember, Brady was booted from working out at a closed public park at the beginning of coronavirus lockdowns ... and he's since helped donate SERIOUS cash to those affected by COVID-19 with his famous All-In Challenge.

As for how the Tuesday work went, regardless ... Brady posted about the effort on social media afterward, talking all about his sweat-soaked shirt.