In what’s been a disturbing trend ever since Los Angeles Lakers center Andrew Bynum demolished Dallas Mavericks guard J.J. Barea with an elbow during the 2011 Western Conference Semifinals, NBA players are letting their emotions get the best of them — on and off the court.

In the span of less than two weeks, we’ve seen three incidents involving Metta World Peace, Rajon Rondo and Amare Stoudemire, resulting in suspensions and a possible playoff-ending injury.

All three incidents featured key players from their respective teams as we get underway with the two-month grind known as the NBA Playoffs.

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World Peace was suspended seven games following a vicious elbow by the Lakers forward that landed flush on the side of Oklahoma City guard James Harden’s head, resulting in a concussion for the soon-to-be NBA Sixth Man of the Year.

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Rondo was suspended one game after he chest-bumped referee Marc Davis during the conclusion of a Game 1 Boston Celtics loss against the Atlanta Hawks.

And, in the most baffling incident of this shortened NBA season, Stoudemire punched a glass case that contained a fire extinguisher, resulting in a laceration and a surgical operation that will likely sideline him for the rest of what should be a short New York Knicks playoffs run.

Chalk each incident up to immaturity and poor judgment on the part of the players — a trend that’s likely to continue as the playoffs intensify. The excuse of players “getting caught up in the moment” doesn’t fly anymore. With the amount of money teams are shelling out to players these days, they can’t afford to not know the difference between right and wrong. Throwing elbows, bumping referees and punching glass containers aren’t just in the wrong category but in the “WTF are you thinking” category.

What makes the recent actions by this trio of players even more alarming is this isn’t the first time they have demonstrated behavior detrimental to their team. We all know World Peace’s involvement in “The Malice at the Palace,” but this marked his 13th suspension in 13 NBA seasons. Granted, the basketball player formally known as Ron Artest did a great job of keeping his emotions in check prior to the Harden incident, but 13 suspensions is still a pretty damning number.

Earlier this season, Rondo was suspended two games for tossing the basketball at an official — which means he got off easy by receiving only a one game ban for his latest outburst towards a referee. The other officials around the league will take notice and Rondo will likely have a shorter leash than most when it comes to arguing with referees. And Stoudemire — dubbed “Glasshole” by the New York Daily News Tuesday — has six seasons of double-digit technical fouls and 101 for his career. To be fair to the Knicks power forward, though, he’s had quite the emotional season following the tragic death of his older brother, Hazell, in a fatal February car crash.

The Stoudemire incident might have been the wake up call that other coaches and players needed. When Lakers head coach Mike Brown was asked if this was a good time to remind his players about maintaining their composure, he said Stoudemire’s injury did all the talking. “Don’t need to now,” Brown said prior to Game 2. “He did it for us. I’m sure guys have taken it into account and have talked about it today.”

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If NBA commissioner David Stern wants to squash this growing problem once and for all, he should make an example out of the next star player who has an outburst during the playoffs. I’m not talking about arguing with the referee over a call or taunting an opposing player. I’m talking about an incident that reflects poorly on the league. Stern had a golden opportunity with World Peace as some armchair commissioners were calling for a ban from the league — which would have been out of line in my eyes. But a suspension from the entire playoffs? Stern’s point would have been heard, loud and clear.

At the end of the day, coaches can only do so much to prevent these incidents from happening. The responsibility lies with the players, who need to start acting like mature adults and not immature, entitled knuckleheads.

Follow Marcus Vanderberg on Twitter at @marcowill