NFL players are really pushing for grass fields following World Cup

While several NFL stadiums do have natural grass fields, it is not a requirement and several teams use artificial fields. 

The benefit for the owners is the artificial fields require less maintenance and have a lower cost. 

Natural grass fields require far more maintenance, often times need to be replaced in-season and cost more money. 

They also are slightly safer for players and have a tendency to produce fewer injuries than the artificial fields. That is the driving force behind the player's push, and given how much money NFL teams make, and how much money they invest in players, it should be a cost they are willing to take on.

Not all of them want to do it.

The World Cup Final is being played at MetLife Stadium in New Jersey on Sunday, and it has one of the most notoriously bad playing surfaces in the NFL. It has been the source of several major leg injuries, and is widely regarded as one of the worst, least popular fields in the league. it has to be infuriating for New York Jets and New York Giants players seeing a natural playing surface installed temporarily for a small handful of games, and then immediately be ripped out for the start of football season.