His assignment against the Texas Rangers comes after two relief appearances -- his debut against the first-place Indians and an encore against the second-place Tigers. Both games went well -- he gave up just one run in a total of 7 2/3 innings.
Buckner began the year with Double-A Wichita and made three starts in his four outings. Then he was promoted to Triple-A Omaha, where the Royals tried him as a reliever for 11 games.
"They just wanted to add another asset to my game. ... They wanted me used coming out of the 'pen," Buckner said.
That went OK. He had a 4-1 record and a 3.60 ERA, but then he was returned to the starting role that he'd had for his first three pro seasons. Overall, he was 9-7 with a 3.78 ERA in 27 Omaha games.
Now, after mulling over their options, the Royals decided to use Buckner as a starter and put Leo Nunez in the bullpen instead. Hence Tuesday's start in Texas.
"I'm looking forward to it. That's what I feel most comfortable with. I've done it the majority of my career," Buckner said.
It'll be a big moment in the 24-year-old's career, but he's trying not to get overhyped.
"I'll definitely have to look at some video and check out the team, but I can't fill myself up with too much of that. I just have to play my game and work well with the catcher," he said.
Buckner doesn't expect any invasion of family and friends from Georgia for the event.
"I don't think so. I'm sure my parents will be watching somewhere somehow," he said.
"Yeah, I think that's what they're going to do," he said.
Smith on shelf: Infielder Jason Smith was out of action for the Minnesota series because of a cut near his right Achilles tendon.
"It feels much better today," he said before Sunday's game. "I'm not limping nearly as much."
Smith suffered a four-stitch cut, apparently from Tigers pitcher Jeremy Bonderman's spikes, when they tumbled together in a close play at first base in the sixth inning of last Thursday's game in Kansas City.
"I hope to be ready for the Texas series," Smith said.
Teahen tees off: Right fielder Mark Teahen, on the disabled list with an elbow injury, took his first full-bore batting practice before Sunday's game.
"I was kind of tentative in the first round," he said. "Then I starting trusting it in the second round and for the rest [of] it, [I] felt pretty much normal."
Teahen hopes to be back in the lineup for Monday's series opener against the Rangers. That's when his 15-day DL stay is up.
Starting pitcher Jorge De La Rosa, also on the DL, is getting over soreness on the left side of his neck that developed while he threw his last rehabilitation outing for Wichita. The left elbow strain that put him on the DL seems to have healed. No time has been set for his return.
Musser on duty: Left-hander Neal Musser, after being stashed away for two days, officially joined the Royals' roster on Saturday and was pressed into service immediately. He worked 1 2/3 innings against the Twins and wasn't charged with any runs, but gave up a two-run double to Mike Redmond. The runs were charged to Brandon Duckworth.
Musser had an extraordinary season in the Omaha bullpen, giving up just three earned runs in 55 1/3 innings for an ERA of 0.49. He didn't permit an earned run in his first 45 1/3 innings.
"Getting ahead and throwing strikes," he said. "You look back and think, 'Wow, that's all you had to do?' It seems so simple."
This is his fifth stint with the Royals this season.
Musser was the only September callup announced this weekend. More are expected after the Omaha and Wichita seasons end on Monday.
Royals rundown: Justin Huber had three RBIs and Paul Phillips hit a two-run homer as Omaha won at Iowa, 8-1, on Saturday. Matt Wright (10-5) and Nate Hoelscher combined on a six-hitter. ... Michael Gaffney hit two homers and Adam Greenberg and Adam Donachie one each, but Wichita still lost, 8-5, at Tulsa. ... Blake Johnson (9-6) threw six shutout innings as playoff-bound Wilmington topped Potomac, 2-1. ... Josh Cribb struck out five in 2 1/3 scoreless innings of relief in Burlington's 2-1 loss at Clinton. ... Mike Moustakas was 2-for-5 for a .381 average, three doubles and five RBIs in five games for Idaho Falls. In the Chukars' 7-2 win over Casper, Zach Peterson struck out nine in four innings, reliever Burke Baldwin boosted his record to 5-1 and Greg Holland notched his sixth save.
Coming up: The Royals move to Arlington, Texas, for a three-game series with the Rangers starting at 7:05 p.m. CT on Monday. Zack Greinke (5-5, 4.07 ERA), is scheduled to start against Rangers right-hander Kameron Loe (6-10, 5.35 ERA).
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.