The NFL is considering adding a “booth umpire” and a senior technology adviser to the referee to assist the officiating crew. The league also is looking at other rules changes, including an alternative to the onside kick.

NFL clubs received a list of potential rules changes on Thursday. Owners will vote on the proposals at the upcoming league meeting to be held by video conference on May 28.

The league’s competition committee told teams last month it supports studying ways to determine how officiating personnel who have access to a video feed could help on-field officials. A booth umpire would serve as an eighth game official. If owners don’t approve adding a booth umpire and/or a senior technology adviser, the league could test a version of both rules in the preseason for possible future implementation.

The proposal that would give teams another option instead of an onside kick permits a team to maintain possession of the ball after a score by substituting one offensive play. The kicking team would attempt a fourth-and-15 from its 25-yard line. This could be done a maximum of two times per game. Onside kicks have become infrequent – and hardly ever successful – since the NFL changed rules on alignments for kickoffs.

Other rules changes that’ll be discussed:

• Making permanent the expansion of automatic replay reviews to include scoring plays and turnovers negated by a foul, and any successful or unsuccessful extra-point attempt.

• Providing the option to the defense for the game clock to start on the referee’s signal if the defense declines an offensive penalty that occurs late in either half. This would eliminate instances when an offense could benefit time-wise from committing a penalty.

• Expanding the defenseless player protection to a kickoff or punt returner who is in possession of the ball but who has not had time to avoid or ward off the impending contact of an opponent.

• Preventing teams from manipulating the game clock by committing multiple dead-ball fouls while the clock is running.

THE NFL IS  moving ahead with plans to begin its regular season on schedule in September, however, the league may play those games without fans in the stadiums due to the coronavirus pandemic.

The league knows it will take a financial hit without those fans. How much of a hit? The league could lose as much as $5.5 billion, according to a report. Forbes.com arrives at the eye-popping amount after estimating the revenue losses from lost ticket revenue, concessions, parking, and merchandise sales if all 17 regular-season games are played without fans. The loss would represent 38 percent of the league’s total revenue.

The Dallas Cowboys would absorb the biggest financial loss, an estimated $621 million in stadium revenue. The loss represents more than half of the team’s $950 million in total revenue. The New England Patriots are second, with an estimated loss of $315 million in stadium revenue, more than half of their total revenue of $600 million.

The Seattle Seahawks would lose $156 million in stadium revenue, which represents 35 percent of the team’s total revenue of $439 million. The San Francisco 49ers would lose $208 million in stadium revenue, which would be 42 percent of the team’s total revenue of $492 million. The 49ers’ loss in stadium revenue is the sixth-highest in the league, according to forbes.com.