A cancellation of the 2020 college football season this fall is unavoidable after the MAC canceled its season earlier in the day, two prominent Power Five athletic directors told CBS Sports on Saturday. Both reacted to the MAC becoming the first FBS conference to cancel its fall season while also referencing a lack of progress fighting the coronavirus, according to their medical professionals.

"It's not fair what we're doing to our coaches and student-athletes," one long-time Power Five AD said. "The sooner we can come to a finality, the better."

"I think it's inevitable [the season will not be played in the fall]," said another veteran Power Five AD.

Neither AD wished to be identified due to the sensitivity of the situation.

The MAC news early Saturday led to speculation that dominoes would begin to fall nationally among the nine other FBS conferences. The FBS is looking more and more like an outlier in forging to ahead to play. UConn, an independent, canceled its season on Wednesday. Several FCS conferences have done the same, to the point that its subdivision may no longer hold a national championship.

More than 30 Power Five players, including multiple potential first-round draft picks, have opted out of playing in 2020 citing health concerns.

"I'm of the opinion it's when, not if [the 2020 season is canceled]," the first AD said. "[The MAC announcement] adds more momentum to the finish line. I think everyone's medical group is now all telling them the same thing. We all keep having the same conversations."

Rumors continued to swirl Saturday that the Pac-12 and Big Ten would indeed be the next FBS conferences to cancel their respective 2020 seasons.

Big Ten presidents met on Saturday, though a league source told CBS Sports not to expect an immediate announcement to cancel its season -- the feeling being that the league wouldn't alter its practice schedule and announce a cancellation on the same day.

The Big Ten on Saturday announced it was "indefinitely" delaying a move to Phase 3 of practice that would have allowed players to use pads. The Detroit Free Press reported that Big Ten commissioner Kevin Warren is believed to prefer attempting to play a season in spring 2021.

Pac-12 presidents will meet in a regularly scheduled call on Tuesday. A Power Five source told CBS Sports they believe the Pac-12 is "very close to voting." That timeline could change in "20 minutes" to organize a conference call if the situation continued to shift, according to one Pac-12 official. 

"The Pac-12 will be next and then the Big Ten," the second AD said. "The Big Ten just going to no contact, what's that going to do for you? With California being so prominent [with the coronavirus], I see the Pac-12 getting out there next."

Four Pac-12 schools were encouraged by state health guidelines that suggested they could start fall practice on Aug. 17 as planned.

"We've all done it. We've all said, 'Let's keep pushing, keep pushing [to play],'" the second AD said. "I thought that was the best strategy. It's certainly not playing out that way. Now, it's just water torture."

West Virginia athletic director Shane Lyons, who is also a member of the NCAA Division I Council and the chairman of the NCAA Oversight Committee, lent perspective to the season going forward this fall.

"I don't want to be the guy who is pushing it just to push it, but we have to understand that -- if we say we're not playing because of a virus until there is a vaccine -- we might as well shut it down for the next two or three years," Lyons told CBS Sports. "Even though a vaccine might come out as early as next year, you don't know if it's going to work. How long is it going to take to get the population?"

There is already the beginnings of a look ahead to spring football. The first AD stressed that eligibility for players participating in the spring would have to be front-burner item before the 2020 season is moved. The first AD said that issue could begin to be addressed as soon as Wednesday when the NCAA Division I Council next meets.

Several schools and conferences have said they would honor the scholarships of any players who opted out of the 2020 season; however, the question has not been answered as to whether those players would get an extra year of eligibility. Athletic departments would conceivably be on the hook for paying for an extra year.

It is speculated -- and should be expected -- that several top draft-eligible players will have already played their last college snap if football is moved to the spring. If the spring season isn't made attractive enough in terms of an extra year of eligibility, several more could decide to sit out.

All sides have to weigh the viability of playing two seasons in one calendar year.

"The eligibility piece is the most important thing to figure out first and foremost," the first AD said. "I don't know what meaningful season we could put together in the spring that would make people willingly burn a year of eligibility."

Whether college football is played this fall is increasingly becoming a case of risk tolerance. We know where UConn set its level. We know where the MAC's risk tolerance stands.

If only one remaining of the nine remaining conferences gets the proper health recommendations to proceed, would it play?

"I think there will be people that will risk it," Northern Illinois athletic director Sean Frazier, a proponent of the MAC's cancellation decision, told CBS Sports. "I can't say they are right or wrong. I'm hoping there is no loss of life or long-term effects."

MAC commissioner Jon Steinbrecher would not speculate whether his conference's decision would cause domino effect with other leagues.

"This decision isn't a financial decision," he said. "It's a health and well-being decision."

The health and safety concerns are becoming more prominent. 

A group of players in at least four major conferences are questioning a safe return of football. Ohio State players on Friday issued a statement separating themselves from that Big Ten protest. 

"We have all chosen to be here," the statement said.