Andersen said there is a "1,000 percent" chance he plays Thursday.
"I'm there," Andersen told reporters. "You're going to need a body bag to keep me from playing."
Andersen hurt the knee during Game 1, missing most of the final quarter.
He will be evaluated by trainers after shootaround. Erik Spoelstra said Andersen's status is still technically day to day.
"I don't take his word for it," Spoelstra told reporters. "We'll actually have to see how he feels [Thursday] when he actually moves around and warms up and I'll talk to our training staff. All of our guys, you ask them immediately after the injury, 'Hey, I'm fine."'
The Heat lead the Brooklyn Nets 1-0 in the second-round series.