Castillo was summoned and told the Twins had just traded him to the Mets for two Minor Leaguers.
The deal that assured Mark Grudzielanek would be playing second base for the Royals in Monday night's game against the Twins.
There had been speculation that the Mets were interested in obtaining Grudzielanek to replace injured Jose Valentin. Ruben Gotay, a former Royal, had been filling in for Valentin.
Meantime, rumors continued to swirl around hot commodity Octavio Dotel, the Royals' closer. Just 22 hours before Tuesday's non-waiver trade deadline, however, he was headed only to his locker to don a Kansas City uniform.
"Seattle and Atlanta," Dotel said, pulling on his shirt. "I heard Atlanta is really strong. What's going to happen? I don't know. Those are just rumors."
High on Nunez: Manager Buddy Bell said right-hander Leo Nunez, who worked six shutout innings in Sunday's 10-0 victory over the Rangers, will remain in the rotation.
"Yeah," Bell said. "For now."
At least Nunez wasn't immediately dispatched back to Triple-A Omaha, as he was after his previous start, which also was impressive.
"He had a good fastball and changeup and threw a couple good sliders," pitching coach Bob McClure said. "He looked aggressive out there, like he was coming right at them."
McClure said Nunez apparently tired toward the end of his 85-pitch outing, and his pitches, which he'd kept low, started rising into a hittable zone.
"He works fast. He reached 94 [mph] and held his velocity all the way," McClure added. "He needs to improve the command of his slider and become more consistent."
After pitching exclusively in relief in 2005 and 2006, Nunez was returned to a starter's role this year for Omaha.
"He's got the makeup for it," McClure said. "He definitely didn't want to come out of the game, which is what you like to see."
Teahen time: Mark Teahen was back in his customary No. 3 spot in Monday night's lineup after being dropped to sixth on Sunday against the Rangers.
The change seemed to work. He had three hits Sunday, including an RBI double in the second inning. Bell suggested that having more time to consider his first at-bat might help Teahen.
"I know I haven't been that successful in the first-inning at-bats in a while," Teahen said.
Now he might try a little trick when he bats in the first.
"You just have to visualize it's the second or the third," he said.
Shealy slam: First baseman Ryan Shealy belted a grand slam in Omaha's 9-5 victory over Colorado Springs on Monday afternoon. Shealy is on an injury rehabilitation assignment. He's been on the disabled list since June 30 because of a hamstring strain.
Royals rundown: Ben Hendrickson worked seven innings, giving up four hits, as Omaha pummeled Colorado Springs, 9-0, on Sunday. Shane Costa had four hits and, Justin Huber hit his ninth home run. Huber is 7-for-13 in his last three games. ... Double-A Wichita's Danny Christensen pitched six innings of a 1-0 victory over Springfield. Adam Donachie hit his third homer in three games for the only run. ... On the other hand, Class A Wilmington lost, 2-0, to Kinston. Even though Rowdy Hardy gave up just one run in eight innings, his record slid to 13-3. ... Jamar Walton (.310) extended his hitting streak to 18 games for Class A Burlington (Iowa) in a 3-0 loss to Quad Cities. ... Zach Evangelho's two hits boosted his average to .344 in Advanced Rookie Level Idaho Falls' 5-2 loss to Orem. ... Alwin Perez of Class A Burlington (N.C.) hit a two-run homer as the Royals won, 8-2. ... In Arizona, four Royals walked in succession in the 17th inning for a 5-4 victory over the Mariners in a rookie league game. Josh Santerre held the M's hitless in the 14th, 15th and 16th.
Coming up: The Royals will meet the Twins in the second of four games at 7:10 p.m. CT on Tuesday at the Metrodome. Left-hander Jorge De La Rosa (8-10, 5.35 ERA) will be matched against Twins right-hander Carlos Silva (8-11, 4.76 ERA).
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.