It was a Monday in mid-June when baseball commissioner Rob Manfred began to backtrack on a guarantee he’d made only five days earlier: that a Major League Baseball season would be played during a global pandemic.

“Unfortunately I can’t tell you that I’m 100% certain that’s gonna happen,” Manfred told ESPN on June 15. “It’s just a disaster for our game, absolutely no question about it.”

Tony Clark, the executive director of the Players Association, blasted Manfred.

“Players are disgusted that after Rob Manfred unequivocally told Players and fans that there would ‘100%’ be a 2020 season, he has decided to go back on his word and is now threatening to cancel the entire season,” Clark said in a statement.

The two sides never finalized a deal and a season only got underway once Manfred unilaterally ordered a shortened 60-game season to begin.

Months later, after myriad challenges along the way — from the Miami Marlins and St. Louis Cardinals teams battling Covid-19 outbreaks early on in the truncated season to teams undergoing constant testing to playing games in empty stadiums — the upstart Tampa Bay Rays and the talent-loaded Los Angeles Dodgers will begin the World Series Tuesday night in Arlington, Texas to determine who will be crowned the 2020 champion.

“If you go back, the commissioner and I and others were saying in March and April that we all thought it was really important to have a season and play,” New York Yankees president Randy Levine told NBC News. “We knew it would be difficult. Under the commissioner’s leadership, all the clubs came together. We first were dealing with science on all levels, and following the lead of health and government officials, making sure there was a clear path to being able to play.”

Levine was part of an advisory board for New York Gov. Andrew Cuomo to help formulate a reopening plan back in the spring.

“We had conversations all over, to learn the best practices — testing, tracing, social distancing, the importance of wearing a mask,” said Levine. “And how to keep the employees safe and the players safe. Rigorous protocols were enforced — and you have to give huge credit to the players, as well as all the baseball staffs.”

Teams received a lengthy manual prior to the season that outlined health and safety measures, including players being tested every other day. Any positive tests resulted in the affected players being quarantined. Mandatory masks were required for managers, coaches and personnel in the dugout, and players sat in the stands, properly spaced apart, during games. All team personnel had to wear masks in hotels during away series and were isolated in those locations during their stay. There were no fans in the stands for the regular season, with many stadiums placing cardboard cutouts in seats to make it look less awkward for fans watching from home.

While Rays manager Kevin Cash was quoted in a late September ESPN story saying, “This isn’t fun,” in reference to the 2020 MLB season, he had a decidedly different take after his team beat the scandal-stained Houston Astros in the ALCS. “Pretty special feeling. I don’t know if I’ve had many better other than getting married and having three kids. This is right there,” Cash told reporters.

Baseball’s spring training was shut down in mid-March, as global sports came to a halt. After a contentious back-and-forth between the MLB owners and the union on numerous labor issues, including how players would be paid in a shortened season, Manfred used his authority to implement a 60-game season. Numerous players across the majors opted out of playing, including Dodgers pitcher David Price and Mets outfielder Yoenis Cespedes.

The first games were played at the end of July, but the season hit a pothole within days when both the Marlins and the Cardinals had to contend with Covid-19 outbreaks. At one point in early August, 18 Marlins players were quarantined in Miami after testing positive for the virus.

“It tells you a lot about we’re suffering,” Marlins shortstop Miguel Rojas, one of the players who had tested positive, said in a video the team posted on social media at the time. Rojas was joined in the video chat by four other teammates who had positive tests.

“We’re human beings, not just baseball players,” said Rojas. “We’re suffering from the virus. This has to bring awareness. Not just to our team, but everybody throughout the league.”

The Cardinals also dealt with an outbreak that upended their regular season, and they had to play 53 games in 44 days. MLB instituted seven-inning double-headers to capitalize on the small time window, and implemented other new rules during the pandemic, such as a runner on second base to start extra-inning games.

Both the Marlins and Cardinals made the 2020 postseason, which featured an expanded, 16-team format. Last Friday, MLB and the union announced no positive COVID tests for 47 consecutive days.

“After the initial fights with the union, everyone came together to get this accomplished,” said Levine. “The teams showed a lot of dexterity with the rescheduling of games. And here we are. During the season there were a lot of critics who said we shouldn’t play. There was a drumbeat for a long period.”

Gene Lamont, a former major league manager who now is a senior advisor to Kansas City Royals GM Dayton Moore, said he didn’t travel with the Royals at all, and has been isolated since March. Lamont said he communicated with Moore by phone. But Lamont said he thought the Royals players were “into it” once the season began, and that the Marlins’ and Cardinals’ situations were a wake-up call.

“When that happened, it was like, ‘Boy, we really have to watch it,’” said Lamont, 73. “For me, it was frustrating not being there, being able to talk to players, other scouts.”

Dr. Scott Braunstein, the medical director for Sollis Health in Los Angeles and who’s been on the front lines during pandemic, attended the 2020 National League Championship Series at neutral site Globe Life Field in Arlington and was encouraged by all the safety protocols that were in place, including how the limited amount of fans were spaced apart in the stadium. Braunstein said that for 2021, MLB might want to consider following some of the same plan as this year.

“Realistically, baseball might not want to try for a whole 162-game season. Maybe meet at middle ground, 100 games,” said Braunstein. “The longer the race, the harder psychologically it would be for players to comply with the way we want them to. And they should continue with regional games, and reduce travel, while implementing every other day testing.”

Tampa Bay starter Tyler Glasnow opposes three-time Cy Young winner Clayton Kershaw in Game 1 of the World Series, a Fall Classic that seemed an unlikely occurrence back in March.