(News Nation/AP) — The Big Ten released its 10-game conference-only football schedule beginning as early as Labor Day weekend but cautioned Wednesday there is no certainty games will be played.

The Big Ten was the last of the Power Five conferences to announce its schedule as college football navigates how to play games amid the coronavirus pandemic.

“We’re approaching this entire process on a day-to-day basis,” Big Ten Commissioner Kevin Warren said on the flagship network. “We’re gathering medical information daily, we’re communicating with all of our constituents in the Big Ten and communicating with student-athletes. This will not be a straight line this year.”

Under the revised schedule, teams will play conference opponents they originally were set to meet and will have one additional cross-division game.

The regular season starts the weekend of Sept. 5 and runs through Nov. 21. There is a built-in cushion allowing for makeup games to be played, if necessary. The 10 games would be played over at least 12 weeks, with each team having two open dates. Nov. 28 also is available for makeup games.

If the coronavirus situation dictates, the season could start Sept. 12, 19 or 26.

The Big Ten championship game in Indianapolis remains scheduled for Dec. 5 but could moved as late as Dec. 19.

The conference will allow teams to begin preseason practices Friday, or earlier if a team’s season begins before Sept. 5.

At least four Big Ten football programs have been impacted by COVID-19. Outbreaks forced the shutdown of voluntary workouts at Ohio State, Michigan State, Rutgers and Northwestern.

“In making this announcement, the conference acknowledges that there is much work to be done on our campuses, in our communities and across the country to gain control of a virus that continues to spread at an alarming rate,” the conference said in a statement. “While the Conference remains hopeful for a September 2020 start in all fall sports, including football, issuing a schedule does not guarantee that competition will occur. While our strategy is to continue planning for all fall sports, if the virus continues to spread among our students despite our many preventative measures, including testing and quarantine protocols, we are also prepared to delay or cancel competition pursuant to local and state public health orders or the recommendations of our medical experts.”

Big Ten competition start dates for men’s and women’s cross-country, field hockey, men’s and women’s soccer and women’s volleyball have been postponed through at least Sept. 5. Conference-only schedules for those sports will be released later.

The conference also released its medical policies and protocols for all sports on testing requirements, and quarantine and isolation. Testing will be managed by a third-party laboratory to ensure consistency across the conference.

Testing frequency will be based on the level of contact risk within each sport and is required for athletes, coaches and staff depending upon exposure to the athletes.

Sports that have a high risk of contact will have a minimum of two tests per week during the competitive season. All other sports will have a minimum of one test per week.

The Big 12 announced this week that its teams would play nine conference games beginning in mid- to late September, with one home nonconference game before that.

Atlantic Coast Conference teams will play 10 conference games and one nonconference game that will be held in the state of the ACC team, with first games the week of Sept. 7.

The Southeastern Conference and Pac-12 are playing 10-game conference-only schedules beginning Sept. 26.

“It would be purely speculation for me to sit here today and say this is what percent I think we’ll have a season,” Warren said. “I know from my standpoint I’m taking this entire process, this entire journey, on a day-to-day basis.”

How many fans will be in the stands remains a question.

Rutgers already has announced that all athletic events would follow state guidelines limiting outdoor gatherings to 500 people or fewer. Maryland said Wednesday it is preparing to begin the season without fans.

Wisconsin athletic director Barry Alvarez sent a letter to season ticket holders saying the school “is preparing for the reality that it will not be appropriate for thousands of fans to gather in Camp Randall on Saturdays this fall.”

Illinois noted that current state guidelines allow for attendance up to 20% of stadium capacity.

Other schools indicated they’d announce ticket or attendance plans later.