Kansas City Royals team president Dayton Moore likened Eric Hosmer debuting with the team in 2011 to an entire organization flipping a switch.

Hosmer, a top-10 overall prospect in MLB at the time, was a key homegrown addition to a Kansas City club that had been stuck in second class for decades. He helped make the Royals a contender and, Moore said, is always going to have a special place in team history. And with Hosmer visiting Kauffman Stadium over the weekend for the first time since leaving in free agency, Moore was feeling nostalgic — and proud — about earlier times during a video conference call with reporters.

“It was just a very significant moment in the history of our franchise and the growth,” Moore said. “The beginning of a new era, and the growth of a team, a player and a team that ultimately won a World Series.”

Acquired by the Boston Red Sox from the San Diego Padres before last week’s trade deadline in an awkward, multifaceted and seismic Juan Soto blockbuster swap, Hosmer tried settling in with a new team — not to mention a storied franchise like the Red Sox — as he faced the Royals for the first time. It was a lot to handle.

Not surprisingly at Kauffman Stadium, Hosmer found reminders of when Kansas City reached MLB nirvana. He saluted grateful fans cheering in the stands before the series opener. He hugged it out with former teammate Salvador Pérez on the field (even as Hosmer dug into the batter's box for his first at-bat). He also stared at the crown-shaped scoreboard in center field that played his career highlights with the Royals, including his mad dash to score the winning run in Game 5 of the 2015 World Series. All of it brought back the best of times during Hosmer’s 12 MLB seasons.

Flags and memories fly forever, but Hosmer still has baseball to play. And he wants to win another ring. He seemingly had a chance to do that with the Padres, although their chances of winning it all also seemed to get better on paper when they traded Hosmer as part of the Soto exchange. Thanks to a clause in his contract negotiated a few years ago by Scott Boras, everyone's favorite sports agent, Hosmer got what he wanted at the deadline: a better chance in Boston (rather than other places) to win.

Just three seasons removed from winning the World Series, the Washington Nationals not long ago would have been a preferred destination for many major leaguers looking for a better chance to win. Now that they've traded Soto (and others) and project to lose more than 100 games this season with little relief on the immediate horizon, Washington's situation was too bleak for Hosmer to consider going there. He refused to waive his no-trade clause.

Hosmer said he didn’t even get into negotiations, like some players do, for more money or guaranteed years because the Nats didn’t have what he wanted.

"It's no offense to (Washington general manager Mike) Rizzo or that organization, but they're in a different part of their rebuild process and I'm at a point in my career where I want to win," Hosmer told Bally Sports. "I thought there would be a better option out there."

The Padres contract has earned Hosmer $21 million for each of the past five seasons, and it could make him $39 million more over the next three unless he exercises an opt-out clause after the 2022 campaign. He has money and security. With Hosmer being the subject of trade rumors in recent years, earlier media reports of his no-trade clause had given at least one incorrect point: They didn't list the Nationals as being on Hosmer's list. But it came out when details of the Soto deal started to leak.

"It was kind of a tough situation," Hosmer said. "It was something that unfortunately kind of got out there and wasn't supposed to."

It was a little awkward, Hosmer conceded, while Padres president A.J. Preller worked on a trade that would send him … somewhere. Imagine having to go back to San Diego after it had become obvious the Padres had tried to trade him. Plus, there was a perception that Hosmer and Boras were holding up the Soto trade. And they might have been, just not forever.

"It was my understanding that everything was going to happen whether I decided to go to (Washington) or not," Hosmer said. "It might have been a little different going back (to San Diego), but the main trade would have gone down no matter what."

Eventually, the deals got worked out, and Hosmer landed with the Red Sox, with whom he had discussed free agency upon leaving Kansas City. Hosmer also recalled how previous Royals ownership refused to match the Padres’ $144 million offer back in 2018, implying that he would have stayed in K.C. otherwise. All of this was on Hosmer’s mind as he flew in the day before the Red Sox-Royals series opener and took in Kansas City from the air. Hosmer said it felt like forever since he'd been in K.C. But it also seemed like yesterday.

Hosmer has missed being with the Royals, saying he always checked the schedule for the upcoming season when it was published to see if he would get back to Kauffman with the Padres. The reunion seemed to take forever, but it also somehow snuck up on everybody too. The Royals still had a good Hosmer highlight video ready to play.

Every plate appearance was an ovation. Every interaction with Pérez — the only other Royals player left from the championship era — was a family reunion. Pérez, in Spanish, called Hosmer his "hermito" (little brother) and "just a great guy and teammate.”

Hosmer got through his first game, going 0-for-3 with a walk and two hard-hit fly balls, including one hit over 100 mph about 405 feet to center (it needed to go at least 410 feet for a home run) and another line drive to right field that just didn't carry.

"There's certain things I didn't miss about this place. That was one of them," Hosmer said jokingly.

On defense, Hosmer also saved an error by teammate Christian Arroyo in the second inning by reaching high for a throw and toeing the first-base bag. It took a replay review by umpires to reverse the call on the field and get it right, but they did. The athletic play was a glimpse of how the Red Sox believe they've improved by adding Hosmer to play first base, where Bobby Dalbec and Franchy Cordero had been platooning.

While he is a Southern California native and San Diego is among the best places to live and work, Hosmer probably would have been OK staying with the Royals all this time, even though Moore probably wouldn’t have changed strategies by spending a lot more money and trying to win more games from 2018 to now. It would have been the Sal and Eric Show at least.

There would be no room for Hosmer on this Royals roster. Kansas City’s first-round pick in 2017, lefty-slugging first baseman Nick Pratto, is just getting to the majors. He was a top-45 prospect and Futures Game selection, not unlike Hosmer a decade ago. Another lefty-slugging first baseman, Vinnie Pasquantino, had a meteoric advancement to the majors this season. Neither have performed well yet overall, but Pratto hit the first walk-off home run of his career last Saturday night and helped the Royals take three of four games from the Red Sox, who are still “in” the American League wild-card race but barely hanging on right now.

Before the series opener, Boston manager Alex Cora said Hosmer anchoring first base made the team better in multiple ways. The Red Sox were criticized in many corners — including by star player Xander Bogaerts — for doing more selling at the deadline than buying. They made the playoffs a year ago, but after a recent bender, they’re hovering around the .500 mark and have many teams to climb over in order to get back to the postseason. So when Hosmer said he wants to win with Boston, it might not happen in earnest until 2023.

No matter, Hosmer can use the trade to flip the switch on his own hitting performance. With the Padres, only sometimes did he live up to the big contract. In nearly 600 games, he batted .265/.325/.411 — a little better than average, relative to the rest of the league. For most of his career, Hosmer has hit too many balls on the ground, even when he was productive with the Royals. His best performance with San Diego came in the pandemic-shortened 2020 season, when he hit the ball in the air for the highest rate of his career and batted .287/.333/.517 in 38 games.

Cora said he is aware of Hosmer’s tendency to stay grounded, and he wondered if playing home games with the Green Monster in left field would influence Hosmer to air it out more often.

“I know everybody gets caught up on the ground balls,” Cora said. “You never know, after that first B.P. at Fenway when he hits a few fly balls to left, he’ll be like, ‘Oh, this is the spot right here.’ He’ll be OK. We are happy to have him.”

Hosmer appreciated the Kauffman Stadium tributes and the confidence his new team has in him, but he is ready to get down to business.

"Glad to get all that stuff out of the way in the most humble way possible," Hosmer said. "Now we can get back to trying to win ballgames, and that'll be the main focus.”