Just over a month after the Big Ten became the first major conference to postpone the 2020 football season, the league reversed its decision Wednesday and announced plans to begin playing the weekend of Oct. 24.

The Big Ten will have medical protocols that include daily novel coronavirus testing and enhanced cardiac screening, the announcement said. The conference’s university presidents and chancellors voted unanimously to play football this fall.

The Big Ten will have eight weeks for regular season games and then a conference championship held the weekend of Dec. 19, just before the College Football Playoff committee’s selection Dec. 20. That weekend, all other Big Ten teams will play another game with the No. 2 team in the East division playing the No. 2 team in the West and so forth. Those games could be tweaked to avoid rematches, and the locations of those games have yet to be determined.

“It’s important that you are in a perpetual process of gathering information, analyzing information, setting high standards and also looking at each other to say that we now have met those standards for our student-athletes to participate,” Commissioner Kevin Warren said during a news conference. “That’s why this is a happy day for us in the Big Ten. … We’ve met standards that we’re very comfortable with for the benefit of our student-athletes.”

Athletes, coaches and other personnel will be tested daily beginning Sept. 30. Any player who tests positive cannot play in a game until at least 21 days after his diagnosis.

Each school will designate a chief infection officer to oversee the testing data. If a team has a positivity rate of more than 5 percent, the team must stop practice and competition for at least seven days. In the case of a positivity rate between 2 and 5 percent, the school should “consider [the] viability of continuing with scheduled competition,” the Big Ten’s announcement said.

“We know that if we can test daily with rapid testing in these small populations of teams, we’re very likely to reduce infectiousness inside practice and game competitions to near 100 percent,” said James Borchers, the head team physician at Ohio State and the medical co-chair of the Big Ten’s Return to Competition Task Force. “We can never say 100 percent, but we feel very confident that with that approach, we’ll be able to make our practice and competition environments as risk-free as we possibly can.”

Penn State Athletic Director Sandy Barbour said the Big Ten will not sell tickets to the general public, but the conference could allow families of players and staffers to attend games.

The conference’s presidents and chancellors previously voted in favor of canceling the fall sports season, citing too much medical uncertainty stemming from the coronavirus pandemic. After the Big Ten’s announcement Aug. 11, the Pac-12 followed suit and punted on fall sports, while the three other major conferences forged ahead. The ACC and Big 12 both opened the season last weekend, and the SEC schedule begins later this month. The Pac-12 is the only Power Five conference that does not plan to play this fall.

The Big Ten faced immediate pushback from some of its coaches and players after its initial decision. A small group of parents held a rally outside the conference’s headquarters near Chicago. Ohio State quarterback Justin Fields, one of the best players in the conference, urged the Big Ten to reverse its decision with a petition that received more than 300,000 signatures. Some Big Ten coaches publicly criticized the conference and voiced their desire to play games this fall.

In response to those outcries, Warren wrote in a letter that the vote by the presidents and chancellors was “overwhelmingly in support of postponing fall sports and will not be revisited.”

The Big Ten did not provide any plans about other fall sports returning to play. The conference’s announcement Wednesday said that updates “will be announced shortly.”

President Trump has advocated that the Big Ten, which spans multiple states critical to his reelection campaign, return to play as soon as possible. He spoke with Warren this month. Both Trump and the Big Ten described the call as a “productive conversation.”

Trump tweeted Wednesday: “Great News: BIG TEN FOOTBALL IS BACK. All teams to participate. Thank you to the players, coaches, parents, and all school representatives. Have a FANTASTIC SEASON! It is my great honor to have helped!!!”

A senior administration official said Wednesday the White House was heavily involved in discussions in the past month to revive the Big Ten season. The official said there were more than 300 phone calls involving administration officials, and Trump spoke with unnamed Big Ten coaches, athletic directors and parents.

The virus, which has killed more than 193,000 people in the United States, continues to spread across the country. In the Big Ten, the counties of four schools — Indiana, Penn State, Wisconsin and Michigan State — are averaging more than 30 new cases per 100,000 people per day, according to Washington Post data. However, the positivity rate threshold that would prevent a team from playing only relates to the number of cases in the program, not in the campus community.

College sports have moved closer toward securing rapid testing, which would help prevent outbreaks within programs. The Pac-12 and Big 12 announced partnerships with health-care manufacturers that provide rapid tests, which is perhaps the most significant development since the Big Ten initially decided against playing this fall. The Big Ten has not announced whether it is partnering with a similar company for testing.

“We are so much better and so much more prepared today than we were 43 days ago,” Warren said.

When the Big Ten postponed the season, the conference’s presidents and chancellors reportedly voted 11-3 in favor of the decision. The conference requires that at least nine of those university leaders vote in favor of the decision for it to take effect, so in this case, at least six members of the council had to change their vote. The unanimous vote to resume play was an important display of agreement within the conference following a month of chaos.

On Tuesday, during a congressional hearing about player compensation, Wisconsin Chancellor Rebecca Blank said the Big Ten postponed the season primarily because of uncertainty regarding the conference’s ability to conduct testing and contact tracing, as well as concerns about myocarditis, the inflammation of the heart muscle that can result from viral illnesses.

If the Big Ten chooses to play this fall, Blank said: “Your first question should be, ‘What’s changed?’ And hopefully we will have answers to exactly the issues that I just raised.”

The Big Ten’s announcement detailed its plans to face the challenges that previously prompted the conference to postpone the season. After a Big Ten athlete tests positive, he will undergo “comprehensive cardiac testing,” the Big Ten’s announcement said. Players will have to be cleared by a cardiologist before they are cleared to return.

Northwestern President Morton Schapiro said that five weeks ago, the medical advice he received indicated there was “virtually no chance” a season could be held safely. Schapiro, one of the 11 university leaders who voted to postpone the season last month, then referenced a quote from economist Paul Samuelson and said, “When the facts change, my mind changes.”

Schapiro said even a week ago he wasn’t confident the conference should move forward with a fall season. Conversations over the weekend with a team of medical experts convinced him that games could be played safely.

“It wasn’t about political pressure,” Schapiro said. “It wasn’t about money. It wasn’t about lawsuits. It wasn’t about what everybody else was doing. It was the unanimous opinion of our medical experts.”

The conferences that have begun playing this season have not done so without problems. Some games have been postponed because of outbreaks in programs. Some teams have played without dozens of players, and even a small number of positive tests in a program can force many more to sit out because of contact tracing.

Multiple Big Ten programs have had to recently pause practices because of coronavirus outbreaks. At Maryland, 46 athletes tested positive, but most of those came from sports outside football, according to two people with knowledge of the situation. The Terps’ football program still had to suspend workouts in early September, and practices resumed Sept. 11. Wisconsin’s football program recently paused team activities for two weeks.

The return of the student body has heightened the risk in college communities. When these athletes began voluntary workouts in June, they returned to mostly empty campuses. Most Big Ten schools are relying on mixed instruction, with some in-person classes and others held remotely.

After at least 342 people affiliated with Michigan State tested positive, the local health department recommended all students self-quarantine immediately through Sept. 26. That type of surge calls into question how well these campuses will be able to contain the virus moving forward and whether the football programs can effectively shield players from the general public.

Big Ten schools will attempt to play nine games in nine weeks, which leaves no room for postponing games. The conference is taking a cautious approach with requiring players who test positive to sit out for 21 days and the relatively low threshold for canceling games.

“We’re going to have to remain fluid,” Warren said. “We’re going to have to adapt to changes. That’s the world that we’re living in. … But the biggest thing: We’re going to need to stay collaborative with each other, transparent with each other, and make sure that we focus on the future and stay together.”

Rick Maese contributed to this report.