"The essential item in our negotiations to host the football game at Wrigley Field was obtaining approval of both universities and the Big Ten for the field dimensions as related to player safety issues," Kenney said in a statement. "The field dimension layout was delivered to the Big Ten approximately eight months ago and was approved by the conference."
Kenney said the field was built exactly to the dimensions previously approved and a conference official performed an on-site visit at Wrigley Field last week. He said there were no issues raised at that time regarding the field dimensions, painted lines and boundaries, which had all been green-lighted by the Big Ten.
"This game would not have been scheduled if it did not pass the strict and meticulous standards of everyone involved, a process that began more than a year ago," Kenney said. "All are in agreement Wrigley Field is a safe venue to host a football game. Other baseball parks, including [Saturday] night's game in Yankee Stadium, feature similar football field-to-venue grid dimensions and rule changes are not considered for football games played in other baseball parks.
"We have reached out to the Big Ten to further discuss the playing field," Kenney said. "While we are surprised by this morning's last-minute statement, all agree that [Saturday] will be an historic event and a wonderful experience for the fans, the schools and the student-athletes."
Illinois sports information director Kent Brown said the close proximity to the outfield wall was a concern.
"A decision was made with both coaching staffs and the athletic directors of both schools and the [Big Ten] commissioner to start every offensive possession and go west," Brown said Friday. "I think it's a student-athlete safety concern that is first and foremost and we want to make sure there's no chance for somebody to run into that wall and get seriously injured.
"It's a unique twist to the game, but I think it's something all parties felt was the most fair," he said.
The last time a team played football at Wrigley was 1970, when the NFL's Chicago Bears called it their home field. At that time, the field ran north-south. The Bears' Bronko Nagurski once ran full speed into the brick outfield wall. Upon returning to the huddle, he reportedly said, "That last guy hit me awfully hard."
Since the Bears played, additional seats have been added at Wrigley along the left-field line, which made the north-south configuration unworkable for the Illinois-Northwestern game.
The Northwestern team did test Wrigley on Thursday during a workout, and Wildcats coach Pat Fitzgerald said he may have different game plans for each end zone to avoid injury.
For Saturday's game, the Big Ten said all offensive plays will head toward the west end zone, including all extra points and all overtime possessions. All kickoffs will be kicked toward the east end zone.
After every change of possession, the ball will be repositioned for the offense to head toward the west end zone.
A coin toss Friday determined that Illinois will occupy the west team bench in the first half and Northwestern will switch in the second half and for all overtime periods.
"The health and safety of our student-athletes is of the utmost importance," Big Ten commissioner Jim Delany said in a statement. "Both Illinois and Northwestern did significant due diligence over the past 18 months, but after seeing the actual layout of the field, all parties felt that it was appropriate to adjust the rules to further enhance the safety of our student-athletes.
"Wrigley Field is one of the most historic venues in the country and playing the Illinois-Northwestern game at this facility will provide a once-in-a-lifetime experience for student-athletes, coaches and fans."