NEW YORK -- NBA referees will be able to call flagrant or technical fouls on defenders who dangerously close on jump shooters without allowing them space to land, as Zaza Pachulia did on the play that injured San Antonio Spurs star Kawhi Leonard in last season's playoffs.

Officials will also make sure jump shooters are in their upward shooting motion when determining if a perimeter foul is worthy of free throws, which could cut down on James Harden's attempts after he swings his arms into contact.

Leonard sprained his ankle when Pachulia slid his foot under Leonard's in Game 1 of Golden State's victory in the Western Conference finals. After calling a foul, officials will now be able to look at replay to determine if the defender recklessly positioned his foot in an unnatural way, which could trigger an upgrade to a flagrant or a technical if there was no contact but an apparent attempt to injure.

"It's 100 percent for the safety of the players," NBA senior vice president of replay and referee operations Joe Borgia said Thursday.

The NBA had made the freedom to land a point of emphasis for officials a few years ago, because of the risk of injuries. But the play got renewed attention during the playoffs because of Leonard's injury and also one in which Washington Wizards forward Markieff Morris landed on Al Horford's foot in Game 1 of their Eastern Conference semifinal series, knocking him out of a game the Boston Celtics rallied to win.

Officials can still rule the play a common foul if they did not see a dangerous or unnatural attempt by the defender upon review. Borgia said Pachulia's foul would have been deemed a flagrant.

With the fouls on the perimeter shots -- often coming when the offensive player has come off a screen and quickly attempts to launch a shot as his defender tries to catch up -- officials will focus on the sequencing of the play. The player with the ball must already be in his shooting motion when contact is made, rather than gathering the ball to shoot such as on a drive to the basket.

"We saw it as a major trend in the NBA, so we had to almost back up and say, 'Well, wait a minute, this is going to be a trend, so let's catch up to it,'" NBA president of league operations Byron Spruell said.