An agreement in principle on a deal that would send point guard Kyle Lowry from the Toronto Raptors to the Miami Heat is "imminent," a league source with direct knowledge of the negotiations said Friday.

The deal, which will consist of the Raptors signing and trading Lowry in exchange for Heat point guard Norris Cole, cash and a combination of future draft picks, can't be officially consummated until sometime after July 1 because Miami is currently over the salary cap and must sort out its position with its existing core of superstars—LeBron James, Dwyane Wade and Chris Bosh.

But James already has opted out of the remaining two years of his Heat contract and the team is aggressively looking to upgrade its point-guard position to persuade James to return. Miami traded up to acquire University of Connecticut point guard Shabazz Napier in Thursday night's NBA draft, but apparently aren't stopping there to show James he will not have to carry the same ball-handling and playmaking duties as he did during the team's failed attempt to snare a third consecutive championship this past season.

Regardless of how the discussions go with James, Wade and Bosh, however, "Lowry will be a member of the Heat" next season, the source said. The Heat's grand plan is to transform its Big Three into a Big Four that would include Knicks free agent Carmelo Anthony, multiple league sources have said. The addition of Lowry, though, could mean only part of the current Big Three comprises the new quartet.

Lowry, a nine-year veteran, put up career highs in points (17.9 per game), assists (7.4), rebounds (4.7) and starts (79) to help Toronto make the playoffs for the first time since 2008 with a franchise-record 48 wins. The exact terms of his deal are being worked out, but its value will be $9-$10 million a year for at least three years. He made roughly $6.2 million this past season.