"We're in the World Series right now, and we've got an outstanding shortstop and an unbelievable center fielder, and that's all I need to know," Yost said after Monday's workout at Kauffman Stadium.
The 2010 Royals had lost 95 games, finished last and Greinke, the 2009 Cy Young Award winner, wanted out. General manager Dayton Moore wanted to emphasize athleticism, defense and, as always, pitching depth.
"Greinke was great, but he made it known that he didn't want to be here, so I think Dayton did a good job of finding what he needed to do to make this team better," left fielder Alex Gordon said. "At the time we were struggling pretty bad."
Yet that deal almost didn't happen. Earlier that month, the Royals were poised to accept a package from the Nationals that, according to The New York Times, included pitchers Jordan Zimmermann and Drew Storen, second baseman Danny Espinosa and catcher Derek Norris. The stumbling point was that Greinke had to waive his no-trade clause and agree to a contract extension, and he declined, because he felt the Nationals weren't quite ready for a breakthrough.
Brewers GM Doug Melvin recalled telling Moore: "Dayton, I think I can give you as good a deal as anybody," and the two had a hush-hush meeting at the Winter Meetings at Orlando. Several days later they had the deal in place.
Cain, just off a .306 rookie trial of 43 games with the 2010 Brewers, was in Miami with his agent when his phone buzzed.
"It was my mom texting me and telling me that she saw I got traded, on ESPN, and actually that's how I found out," Cain said. "I didn't know much about Kansas City. Once I got here, I heard mostly about how they'd been losing, [but] the team embraced me and I ended up getting a chance, so they've definitely been patient with me through all the injuries, and I've just been trying to make up for lost time."
Has he ever. Cain hit .301 this season with 53 runs and 28 stolen bases and, as of Sept. 13, wound up batting third. In 22 games in the three-hole through the postseason, he's hit .333 with 11 RBIs and six steals.
When the trade was made, Escobar had just finished his first year as the Brewers' regular shortstop.
"Before my first full season, 2010, they traded J.J. Hardy to Minnesota and they said, 'Now you'll play shortstop every day,' and I felt comfortable, happy," Escobar said. "Then they traded me after that year and I asked, 'Why did you tell me that? You traded me.' But I came here and forgot about that. Now I love this team.'"
Escobar this season hit .285, knocked in 50 runs, scored 74 and swiped 31 bases. When Yost revamped his lineup, Escobar went into the leadoff spot, and in 23 games there, he's hit .340 with 13 runs and seven RBIs.
"I've been rooting for them," Melvin said. "I think it's just a credit to our farm system and player development, when you take two raw kids like Escobar and Cain and they spend most of their time in our system. It shows that it can be done. Those are the stories that I love to see."
Yost, then still a front-office advisor with the Royals, remembered Escobar and Cain from his years as Milwaukee's manager and recommended to Moore that they be included in the Greinke deal.
"From the minute I saw Escobar in Spring Training as an A-ball player, the kid was as big as a broomstick, and he just covered the whole left side of the infield," Yost said. "He was making fantastic plays as a kid out of A ball. I fell in love with him, and I knew when he filled out, he'd be a really good offensive player, because his hands worked."
Melvin remembers Cain from those formative years.
"How raw and crude he was, but a great personality," Melvin said. "It just goes to show you that patience pays off with young players."
At that point, Moore was willing to wait for Escobar and Cain to develop further.
"The deal worked perfectly for both organizations," Moore said. "We got what we needed, we got players for the future, they got a Cy Young Award winner that helped them get back to the playoffs for the second year in a row. So it was good for everybody."
It got even better for the Royals because, on Dec. 9, 2012, they were able to obtain pitchers James Shields and Wade Davis from the Rays in a trade for prospects, a deal that included Odorizzi along with outfielder Wil Myers. (Earlier that winter, Jeffress was dealt to Toronto; is now back pitching for Milwaukee.)
Kansas City fans viewed the Tampa Bay deal with skepticism, especially after Myers became the 2013 American League Rookie of the Year and the Royals, with Shields and Davis, finished in third place. Now, obviously, the consensus has shifted along with the Royals' stunning success.
"Us and Kansas City, we kind of mirrored each other," Melvin said. "We were just a few years ahead of them at the time. They traded Greinke for young players, and then they traded young players for Shields. I think they looked at what we did and said, 'When you have an opportunity, you have to try to capitalize on it.'
"I don't think we would [second-guess] any of those trades, and I don't think they should look back on trading Wil Myers and Odorizzi [for Shields and Davis], either. It's very similar. I'm happy for them."
"When you sit back and look at it, the Escobar and Cain trade was the one that put us in position to start our championship climb," Yost said. "The Wade Davis and Shields trade was the one that got us here. I don't think we'd be here right now without either one of those trades."