CHICAGO  Saturday’s college football game at Wrigley Field between Northwestern and Illinois was shaping up to be an unusual game. But on Friday the Big Ten announced a series of safety-related changes that promise to make the game even more memorable, no matter its location.

After seeing the tight configuration required to fit a football field in the home of the Chicago Cubs, Jim Delany, the commissioner of the Big Ten, announced that the teams would run all of their offensive plays in one direction, toward the western end zone. Every time the ball changes hands, the players will be turned around so the action heads west  toward the third-base dugout and away from the right-field wall.

The move followed a number of news reports that questioned whether the tight east-west configuration of the football field at Wrigley might cause an injury. For instance, a corner of the eastern end zone is less than two feet from the wall in the right-field corner. The back of the center of the eastern end zone is six inches from the right-field wall, and the uprights are attached right to the wall. (The other goal post stands in front of the third-base dugout.)

Both teams had signed off on the layout, and the configuration had been made public, but members of the news media were able to walk and photograph the field for the first time on Wednesday. Then the safety issue became a prime topic on college football blogs, overshadowing the event’s main attraction as the first football game to be played there in nearly 40 years.