He got his hair cut by "the haircut guy from back in the day." He said hello to Oxygen Dave, his "favorite fan ever." And, most importantly for him, he threw a great game, allowing just one run over seven innings.
Just like old times.
Greinke earned a no-decision in the Brewers' 2-1 loss to the Royals on Tuesday night, but he had plenty to say after the game about the place he called home for seven seasons.
"It was exciting," Greinke said of pitching again in KC. "It wasn't any more [exciting] getting ready for the game or anything, but probably it started earlier. When I woke up, I was probably a little more excited than usual. Once I got to the park, it was the same. And once I was on the mound, it was the same, too."
He was certainly the same on the mound. Greinke allowed six hits and struck out eight. His lone mistake was a leadoff home run to Alex Gordon, one of the few players remaining from the Greinke era.
Greinke was pleased by the reception he received from the Royals faithful. Despite some booing, his name was greeted with plenty of cheers. He also spotted a couple fans wearing his jersey, something he said wasn't necessarily the case when he pitched for the Royals.
"I noticed one, maybe two [on Tuesday]. That was cool. I remember when I was here, there were more people wearing [Jeremy] Affeldt jerseys than our new stuff."
Greinke's return was probably a bigger deal for the fans than for him. In 2009, Greinke was an All-Star for the Royals and won the Cy Young Award. A year later, he asked to be traded, and one of the team's most promising players was soon wearing a different uniform. Some fans weren't pleased with the way he requested the trade.
He just said "maybe" when asked if he regretted anything he said, but he said he only acted that way out of necessity.
"I felt like the only way would be to force myself out," Greinke said. "I don't think anyone would have been able to trade me if I was, like, this great guy, so I had to give them motivation to do it."
When a reporter brought up the possibility of Greinke returning to play for the Royals -- a possibility broached considering Greinke's potential free agency at the end of the season -- the pitcher was happy to hear that fans would be receptive to him.
"It's nice [that people would want me back], because I was pretty rude on the way out," Greinke said. "I felt like I had to in order to get out. I didn't want to have to be the bad guy, but I felt like I had to be. But I liked it here. The fans were great."
Greinke went on to compliment the fans' loyalty to a team that hasn't produced many winning campaigns in recent years.
"I don't know how so many of them come to the games when they've been bad for so long, but it's pretty impressive," Greinke said. "I think they're beating five or six teams in the American League [in attendance]. Some teams are really good, and Kansas City's outdrawing them. It shows you how, for all that they've been through, to still come out is pretty cool."
When a player returns to his former place of employment, it's typically all about visiting with former teammates. For Greinke, who didn't see too many friendly faces in the opposing dugout due to roster turnover, that wasn't the case.
"I've talked to a lot of them since in other places. There's no real reason to now," Greinke said. "I don't really like talking to the other team. ... Occasionally I'll wave, but I just don't think you should be doing that very often."
Greinke was once the key building block for the Royals, but now that he's gone, the buzz seems to be circulating around the Royals' rebuilding efforts. And Greinke's noticed.
"Some of those guys are pretty good hitters, a lot of power it seems like," he said. "I don't know if their power numbers have been really good, but you know it when you're facing them that you can't really make a mistake or else they could do some damage. There's some holes, but they've got a lot of strengths."
Are the Royals better now than when he played in Kansas City?
"Offense-wise, yeah they are. Defense-wise, I know they got [Alcides] Escobar and [Lorenzo] Cain, and there's some more defensive-minded guys," he said. "Probably, offensively and defensively. Pitching's probably about the same. Bullpen, it's good now. I felt like they were pretty good when I was there, too, those couple of years. It might be better now. I think they have the best bullpen in baseball. I'm not positive."
As Greinke's open-mic night wound down, someone brought up the fact that he hasn't sold his Kansas City house yet. Was it some kind of an omen that he'd one day return?
"That has nothing to do with anything. I'm sorry to break it to everyone," Greinke said. "We got a two-year lease, so it was like, 'Might as well rent it out.' We like it. When I got married, it was our first home, so my wife doesn't really want to get rid of it either."
Vinnie Duber is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.