Dwyane Wade og Chris Bosh til Miami Heat

Both players are expected to get the maximum amount allowable under the league's collective bargaining agreement, though the addition of James could change the players' salaries. Contracts cannot be officially signed until July 8.

It was not immediately clear whether Bosh will sign with Miami outright or join the Heat through a sign-and-trade deal. Bosh could earn $125 million over six years via sign-and-trade, but only $96 million over five without it.

"Either way, he's definitely going to Miami," the source said.