The Pac-12 announced Friday that several fall sports, including football, will only play conference games this year because of the novel coronavirus pandemic. The Big Ten announced the same decision Thursday.

The Pac-12′s decision, which the conference said will delay the season’s start date, also affects men’s and women’s soccer and women’s volleyball. The conference is delaying the start of mandatory athletic activities.

“The health and safety of our student-athletes and all those connected to Pac-12 sports continues to be our number one priority,” Pac-12 Commissioner Larry Scott said in a statement. “Our decisions have and will be guided by science and data, and based upon the trends and indicators over the past days, it has become clear that we need to provide ourselves with maximum flexibility to schedule, and to delay any movement to the next phase of return-to-play activities.”

Later Friday, the Pac-12 announced Scott had tested positive for the coronavirus. The league said Scott, 55, was self-quarantining at the direction of his physician and is still performing his commissioner duties as normal.

The Ivy League announced Wednesday that it will not hold sports during the fall semester, becoming the first Division I conference to suspend its football season this year. This week’s announcements have served as a sobering reminder that the entire college football season could be in danger.

“We may not have sports in the fall,” Big Ten Commissioner Kevin Warren said on the Big Ten Network. “We may not have a college football season in the Big Ten.”

The Pac-12 said details on the conference-only schedules will be announced by July 31. Pac-12 football programs typically play nine conference opponents during the season.

The conference said athletes who choose not to participate in sports this year because of health concerns will have their scholarships honored by their university.

The implications of the Big Ten and Pac-12 moving to conference-only schedules ripple across college football. The schools previously planning to play Pac-12 teams during their nonconference schedules are now left without opponents. Some of those issues will be resolved if other conferences follow suit and also cancel out-of-conference games.

Notre Dame, which is not a member of a football conference, has lost games against Southern California, Stanford and Wisconsin. BYU, another school that doesn’t play in a conference, had three Pac-12 opponents on its schedule.

Southern California was also scheduled to open the season against Alabama at AT&T Stadium near Dallas. Alabama Athletic Director Greg Byrne said in a statement Friday evening: “With the Pac-12′s decision to move to a conference-only schedule, we will do our best to adjust. What that looks like is to be determined.”

ACC Commissioner John Swofford said Friday that the conference expected to have a decision about its fall sports season by late July.

Most college football programs began holding voluntary workouts in June after the NCAA lifted the suspension on team activities. But in the following weeks, a number of schools have announced coronavirus cases within their programs, and some have had to temporarily pause workouts.

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