The Miami Heat retained free-agent center Hassan Whiteside on Friday, and they remain in the mix for free-agent forward Kevin Durant.

But what about their franchise cornerstone -- the guy who was there for the NBA titles in 2012, 2013 and 2006, and who has been there since he was drafted fifth overall in 2003?

Yes, Dwyane Wade also is an unrestricted free agent, and he apparently has grown tired of waiting for the contract offer he wants from the Miami Heat. It started with a couple intriguing tweets Friday morning:

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Rival teams starting to take Dwyane Wade's free agency seriously, w/ GM's telling @TheVertical they've made multi-year offers to his reps.

— Adrian Wojnarowski (@WojVerticalNBA) July 1, 2016

Sources: Rival execs expected to speak with Wade on phone today, armed with belief his contract impasse with Heat has him considering move.

— Adrian Wojnarowski (@WojVerticalNBA) July 1, 2016

And by the end of the day, Yahoo Sports reported Wade was getting $20 million-a-year interest (for multiple years) from several other teams around the league. Specifically, the Chicago Bulls, Denver Nuggets, Dallas Mavericks and Milwaukee Bucks.

Re-upping with Wade, 34, clearly was not the Heat's top offseason priority, perhaps because they figured they could circle back to him eventually. But the 12-time All-Star clearly has set his sights higher than the one-year, $20 million deal he signed last summer.

Is Wade just looking for some leverage here, or would he really consider leaving the only franchise for which he has played? We should find out soon.