St. PETERSBURG, Fla. -- Alex Cora began his Thursday with a morning run to CVS to buy diapers for his 8-month-old twin boys. He ended the day by standing in front of television cameras and defending a move he made -- in this case, actually, it was one he didn’t make -- in the late innings of a game.

Just another day in the life of the manager of the Boston Red Sox.

It just so happened that Thursday was the first game of Cora’s first season on the job. No manager ever forgets that first game. From the pregame introduction and the jog through the handshake line to delivering the lineup card to home plate and making the first pitching change, the senses are more heightened, the emotions acute.

“There’s definitely anxiety there,” said Red Sox bench coach Ron Roenicke, who managed the Milwaukee Brewers from the start of the 2011 season until he was let go 25 games into 2015. “Once you get into the first game it gets better. And then once you get your first win, it gets a lot better.”

Cora was six outs from win No. 1. The Red Sox made two mistakes on the bases and ace Chris Sale didn’t have his sharpest command. But Sale still blanked the Tampa Bay Rays for six innings, and the Red Sox took a four-run lead into the bottom of the eighth under the dome at Tropicana Field.

That’s when it all went haywire. Reliever Joe Kelly walked the leadoff batter, gave up an RBI double, then issued two more walks to load the bases in a performance that he labeled “pathetic.” Rather than calling for All-Star closer Craig Kimbrel to get loose, Cora summoned setup man Carson Smith, who walked in a run and gave up Denard Span's three-run triple.

The Red Sox lost, 6-4, and Cora received a different kind of first: An inquisition from the media. The first question, predictably, involved Kimbrel not leaving the bullpen.

“We talked about it before the game. I’m not going to put him in that spot right now,” Cora said. “We feel he’s ready, but I don’t think it’s fair for him to come in in that situation. It’s not a clean inning. It’s something that, we map it out, talk about it and stick to it.”

There were follow-up questions, of course. Cora didn’t flinch. Yes, he said, Kimbrel was available. Just not for more than one inning, Cora reiterated. Not after Kimbrel took leave of the team for three weeks in spring training to be with his infant daughter at Boston Children’s Hospital, where she had surgery to address a congenital heart condition.

Cora could have brought in Kimbrel after Kelly loaded the bases with a three-run lead or after Smith walked in a run to trim the margin to 4-2. It was arguably the highest-leverage situation of the game, and Kimbrel is far and away the Red Sox’s best reliever.

“For what we’re trying to accomplish here, we need him for the long run and not just for one out on Opening Day,” Cora said. “When that situation presents, probably later [in the season], we’re talking about in 15 days or something like that when he’s really ready, he’ll be in that situation.

“I’m not going to change my mind because there’s a lot of stuff going on [at that point in the game].”

Indeed, Cora didn’t waver. According to Roenicke, he was resolute in sticking to the pregame plan. He kept Kimbrel’s long-term health in mind, and at the same time, showed confidence in Smith, a late-inning reliever whom the Red Sox will need for similarly hairy situations throughout the season.

“When you’re taking care of guys and you decide that’s what you’re going to do, you stick with it,” Roenicke said. “He did the right thing. We just didn’t pitch as well as we know we’re going to pitch the rest of the season.”

Kimbrel has always preferred pitching in the ninth inning. He came through the minors as primarily a one-inning closer and doesn’t feel as comfortable with getting four- or five-out saves.

But that’s a topic for another day. Cora, who is inclined to manage his bullpen according to individual matchups and eschew traditional roles, has said he hopes to use Kimbrel in innings other than the ninth, perhaps even at the expense of a few saves. Eventually, it will be up to Kimbrel to adapt.

On Opening Day, though, after Kimbrel’s abbreviated spring training, it wouldn’t have made much sense to push it.

“We have 24 [other] guys,” Cora said near the end of a 6½-minute grilling, the likes of which grayed Cora’s Red Sox predecessor John Farrell. “We have 162 games, so we’ve got to think about our players and take care of them. I think that’s the best way to take care of [Kimbrel] right now.”

Cora said he slept soundly on Wednesday night, even with the anticipation of Opening Day and the impending arrival of so many friends and family members to share it with him.

Odds are he had a tougher time getting to sleep Thursday night knowing how close he was to that first win before it slipped through his fingers.

“It’s going to happen,” Cora said, matter of factly. “I guess I got this one out of the way right away.”

There will be other difficult days, probably more than Cora wants. But that’s life as the manager of the Red Sox. It’s Cora’s new reality.