Red Sox manager Alex Cora was just days away from making a decision on who his closer would be for the start of the 2021 season.

Instead, the decision was made for him.

Cora revealed on Saturday morning that closer candidate Matt Barnes, perceived by some as the favorite to win the job, tested positive for COVID-19.

The hard-throwing righty and longest-tenured member of Boston’s bullpen will have to quarantine away from the team for at least 10 days, knocking him out of Opening Day, which is scheduled for Thursday at Fenway Park against the Orioles. Barnes was unscored on in all five of his Grapefruit League appearances, striking out eight.

Veteran Adam Ottavino, the other strong candidate in the closing mix, is likely to handle the ninth inning when the season starts.

In the process of contact tracing, the Sox had to scratch Matt Andriese from his Saturday Grapefruit League start against the Pirates. Minor Leaguer Andrew Politi replaced him.

It was a whirlwind morning for Cora, who learned of the positive test at 7 a.m. ET.

“Everything happened this morning. So we’re still scrambling as far as what we’re going to do,” said Cora. “We know how we’re going to attack this, obviously. There are some guidelines and the organization is great about stuff like that. It’s unfortunate, but this is the world we’re living in and we have to make adjustments.”

The Red Sox hope that there isn’t a ripple effect and that the players who were near Barnes test negative in the coming days.

There is also the matter of contact tracing, and how that might impact who is available for the start of the season.

“There’s a chance that some of the guys that are in contact tracing might be able to be in the Opening Day roster,” said Cora. “So we just have to get more information throughout the day. Obviously, communicate with MLB and the committee and go from there. We just have to be patient throughout the day to get more information about it. Hopefully instead of adding people to it we subtract people from that list, but we have to be very careful, as you know.”

Cora didn’t hide the fact that the situation is unsettling, especially this close to the start of the season.

“It’s nobody’s fault. That’s the first thing. They’ve been very responsible,” said Cora. “We’ve been praising them throughout camp. It just happened. You start thinking about, ‘What if something else happens? Where are we going to be in a few days?’ It’s not comfortable, but at the same time, if we keep doing the things we should be doing, the hope is we’re going to be fine as a group.

“It’s one isolated quote-unquote incident. Let’s hope that’s the case. But it’s a different mood, to be honest with you. It’s not a good feeling. But we’re trusting the process, trusting our medical staff, trusting the testing system.”

The tracking system that MLB put into place for this season should help the Red Sox prevent an outbreak.

“There’s a process and they talk to Matt, what he’s done the last three or four days, obviously you have the information from the trackers, but at the same time he’ll go over what he did from breakfast to dinner, who he spent more time with, and from there they keep adding or subtracting people,” Cora said.

For weeks, the Red Sox were enjoying a smooth camp with little to no hiccups. But in recent days, catcher Christian Vázquez suffered a contusion and laceration under his left eye after being struck by a thrown ball during a drill and ace Eduardo Rodriguez was scratched from pitching on Opening Day due to a tired arm. And then came the capper on Saturday.

“We sign up for this, this is the world we live in, you know? This is not only the Boston Red Sox, it's happening everywhere,” said Cora. “We’ve just got to stay the course. We still have to stay disciplined and hopefully this is just something that, in a month, two months, we look back and we're like, 'You know what? That was it,' and we move forward.”