About an hour before tipoff, the team announced that Adebayo -- who was listed as questionable for Tuesday's game because of a neck strain -- will play after missing Games 2 and 3.
Heat point guard Goran Dragic, who has been dealing with a foot injury and also missed the past two games, was ruled out for Game 4 against the Lakers. He was listed as doubtful before being declared inactive.
Adebayo said Monday that he was attempting to "get back as quickly as possible," but noted the team is "trying to make sure I'm safe and I'm ready to play."
"To be in the Finals and the medical staff is telling me I can't play ... it sucks, but I understand," said Adebayo, who also has been hampered by a shoulder injury.
Meyers Leonard started at center in each of the past two games for the Heat, who trail the Lakers 2-1 in the championship series. Kelly Olynyk -- another 7-foot big man -- scored 41 points off the bench in the last two matchups with Adebayo and Dragic out.
Tipoff between the Heat and Lakers is set for 9 p.m. EST Tuesday inside the NBA bubble near Orlando, Fla.