LAS VEGAS — It has become a cottage industry for the Miami Heat and could prove fruitful again for Pat Riley.

NBA Commissioner Adam Silver, however, is not particularly a fan of the practice, while not addressing particular protagonists.

With Riley having built his front-office reputation, at least in part, on seizing upon players who want out elsewhere — Alonzo Mourning, Shaquille O'Neal, Goran Dragic to name a few — and now possibly to again strike with disgruntled Oklahoma City Thunder guard Russell Westbrook, Silver said the increasing practice of players demanding and even forcing trades has become "disheartening."

While Westbrook has not publicly demanded a trade, it was the request and ensuing trade of former Thunder teammate Paul George last week to the Los Angeles Clippers that now has Westbrook seeking relocation, with the Heat among the suitors.

"First of all, you know, of course, that's nothing new in the league in terms of trade demands," Silver said of the trend that also led to Anthony Davis being traded from the New Orleans Pelicans to the Los Angeles Lakers. "But it concerns all of us. I mean, it falls in the same category of issues of the so-called rule of law within a sports league: You have a contract and it needs to be meaningful on both sides.

"On one hand, there's an expectation if you have a contract and it's guaranteed that the team is going to meet the terms of the contract, and the expectation on the other side is the player is going to meet the terms of the contract."

Except, of course, when trade demands fracture franchises.

"I will say, without getting into any specific circumstances, trade demands are disheartening," Silver said during his state-of-the-league comments at the Las Vegas summer league, where the Heat continue play. "They're disheartening to the team. They're disheartening to the community and don't serve the player well. The players care about their reputations just as much.

"And so that's an issue that needs to be addressed. There's not a simple solution there. This is a talent-driven business. Players have leverage. They have economic power of their own. But that's what Collective Bargaining Agreements are for — to sit down and come up with a set of rules that are sensible and fair for everyone."

Silver also addressed the preference of players to relocate to teams in New York, California and Florida, with Jimmy Butler agreeing to join the Heat at the start of free agency.

"I'm mindful of this notion of balance of power and, I think, it applies in many different ways," he said. "An appropriate balance of power between the teams and the players, an appropriate balance of power I'd say among all our 30 teams, big markets, small markets, some markets that are perceived as being more attractive than others, tax issues, climate issues. At the end of the day, you want to make sure you have a league where every team is in a position to compete."