Sweeney, now a special assistant to general manager Dayton Moore, has been spotted behind the cage during batting practice throughout the playoffs, dressed in a suit and tie, shaking hands with friends and colleagues and seeming to genuinely enjoy himself in this environment.
But you have to wonder if this doesn't sting just a little. Brett knows the taste of victory, having won the ultimate prize with this team 29 years ago. But Sweeney was here for some very lean years, having debuted in 1995 and remaining a loyal Royal through 2007.
During that stretch the Royals had one winning season, going 83-79 in 2003. That was followed by three consecutive 100-loss seasons, and in his final year with the Royals, 2007, they finished with a 69-93 record.
Although he doesn't feel any pangs watching the 2014 Royals make their frenetic push through October, it does serve as a reminder that he wasn't able to do the same with the organization when he was in uniform. In that respect he's glad to be contributing in some way to today's club.
"I had some great years, personally, and some people say I set some records that will never be broken here," Sweeney said. "But in the same breath, at the end of the year, I always felt totally empty because we didn't have a chance to put a [championship] flag up in left field. That's the only reason I played Major League Baseball, was to win."
He certainly did his part. As a Royal, Sweeney batted .299 and belted 197 home runs. His peak seasons were 2000, when he drove in 144 runs, and 2002, when he batted .340, the second-highest average in club history behind Brett's .390 in 1980. Sweeney was an All-Star five times (2000-03, '05) and ranks among the top six in 17 offensive categories.
He was also an example-setter, playing the same way every game -- hard and steady -- regardless of where his team was in the standings.
Sweeney recounted a conversation he had late one season with teammate Mark Teahen, who a month earlier had been traded to the Royals.
"He said, 'It's August 20, we're 20-some games out of first place, and you're moving the guy over from second to third in the third inning, then you're diving headfirst into second base with a bad back, and you're on the top step cheering like crazy when we go ahead,'" Sweeney recalled. "'These games don't mean anything. How do you do it?'
"I said, 'Mark, there's only one way I was taught to play this game -- to win. These are the seeds that I have to plant for the next generation. We have to play this game the right way.'"
Sweeney did make it to the postseason -- for the first and only time -- in 2010, when he was with the Phillies to wrap up his 17-year career. He singled in his lone at-bat, a base hit in the National League Division Series against the Reds.
It was around that time when he started talking with Moore about life after baseball.
"I said, 'Dayton, my only void in my whole career was not bringing a championship flag to Kansas City,'" he said. "'My playing career is over, and I will never be able to be a part of that, but I would love to be a small part of this organization. Whatever you want me to do, put me to work.'"
Sweeney joined the team in an official capacity in February of this year, named a special assistant in baseball operations. He and his wife are considering relocating their family, which includes five kids, from their home in San Diego back to Kansas City.
"Even though I'm not out there hitting balls or making plays at first base, I still feel so connected to this team," he said.