Bill Leavy’s NFL officiating crew attended the San Diego Chargers' practice this week, speaking to players, coaches and the media about the new rule changes for the upcoming season.

You can see the same video the players watched on the rule changes by clicking here.

Leavy’s officiating crew worked a couple practices and Saturday’s scrimmage this week in San Diego, so Chargers head coach Mike McCoy had some opportunities to see the new rules in action before Thursday’s exhibition opener against Dallas.

“It’s great to have them here because that’s the way the game is going to be called,” McCoy said. “We don’t stop periods in practice for sacks and certain things because we can see that.

“We teach our players to run by the quarterback in practice so we don’t hit his arm. But they’re trained to blow the whistle the way it’s going to be in a game, so it’s good for the players to see that.”

The following are a couple of the most significant rule changes and how they will affect the Chargers and other teams this season:

Look for more defensive holding calls: Leavy said he felt the most impactful rule change will be the calling of illegal contact and defensive holding.

According to the new rules, defenders cannot initiate contact with receivers after 5 yards downfield when the quarterback is in the pocket with the ball.

Leavy told us that NFL brass does not want jersey pulls and tugs from defensive players on offensive players. So if referees see jersey pulls, they are supposed to call it. Leavy said referees used to factor in whether or not the jersey pull impeded the receiver. But now officials cannot factor that into whether or not they will throw a flag.

As a result, expect to see a lot more defensive holding and illegal contact calls during preseason play. Defensive holding is a 5-yard penalty and automatic first down. Illegal contact also is a 5-yard penalty and automatic first down.

Officials also have been told to watch receivers pushing off at the top of the route to gain advantage. That call will result in offensive pass interference, a 10-yard penalty.

Mike Pereira, former vice president of officiating for the NFL and now a rules analyst for Fox Sports, said via Twitter that the last time the league had this rule as a point of emphasis in 2004, the number of illegal contact fouls went from 79 to 191.

The new rules should affect aggressive defenses like Seattle and Kansas City that play a lot of press coverage. But it also can have an impact on veteran cornerbacks like Brandon Flowers and Richard Marshall, who both use physicality to redirect receivers during the route.

Watch out for hands to the face: A rule clarification states that in close line play, illegal use of the hands to the face will be called if direct and forcible contact is made to the head, neck or face of an opponent, regardless of whether it pins the head back or is prolonged.

Hands to the face by a defensive player will be a 5-yard penalty with an automatic first down. Hands to the face by an offensive player will be a 10-yard penalty and repeat the down.

“The hand to the face does not have to be prolonged, and it does not have to pin the head back,” Leavy said. “If we see force and it moves the head, even they take it off it, they want that to be a foul.”

The new rule could affect taller linemen who have a higher strike zone target when they go to initiate a block, although I talked to 6-foot-6, 335-pound Chargers defensive tackle Kwame Geathers about the new rule and he said he’s never had a problem with it in the past.

No more dunking the football: Basically, the new rule prohibits players from using objects on the field as a prop in part of their end-zone celebrations. So players cannot dunk or shoot the football over the crossbar.

They also cannot pretend to putt the football with a pylon or use the ball as a prop in any other manner. Players can still spike the football and dance individually after a score, but no choreographed dancing between more than one player, and more than one player cannot jump into the stands, like the Lambeau Leap.

Recovery of a loose ball in the field of play: Recovery of a loose ball is reviewable anywhere on the field of play and includes fumbles, backward passes and kicks. In the past, the play was only reviewable in the end zone or on the sideline.

Basically, this is the NaVorro Bowman rule. The San Francisco middle linebacker recovered a fumble by Jermaine Kearse during the NFC Championship game last season but had the ball taken from him on the ground by Marshawn Lynch after he injured his knee in a pile-up.