The left-hander was called up from Triple-A Omaha ahead of Tuesday night's game against the Mariners for his Major League debut.
Verdugo was on the active roster earlier this season, but he didn't make an appearance in his two days with the Royals. At Omaha, Verdugo appeared in 18 games (15 starts), going 6-2 with a 3.58 ERA. In five years as a Minor Leaguer -- four in the Giants' system -- he's 27-9.
"No. 1, he was available to pitch. No. 2, he's got pretty good numbers at Triple-A," Royals manager Ned Yost said. "He's done a nice job [at Omaha]. He's on the roster, and we wanted to take a look at him."
Oddly enough, Verdugo's promotion comes as Sanchez was designated for assignment. The two pitchers were acquired by Kansas City in the same trade this offseason from the Giants in exchange for outfielder Melky Cabrera.
In addition on Tuesday, the Royals called up right-hander Vin Mazzaro, who will be used in a relief role, and optioned outfielder Jason Bourgeois to Omaha.
Mazzaro has been up and down between Kansas City and Omaha several times this season. He's appeared in eight games for the big league club, including six starts. He's 3-3 with a 5.70 ERA, allowing 20 runs in 30 innings.
Bourgeois was finding playing time hard to come by since Lorenzo Cain returned from injury to reclaim the everyday center-field job. After seven games in April, Bourgeois was optioned back to Triple-A. He returned on June 27, and appeared in only 12 games. Lately, Bourgeois served as a pinch-runner and did not have a plate appearance since July 6.
"Didn't really want him here as a pinch-runner," Yost said. "We needed pitching. We had to have the spot for pitching. If something happens to one of our outfielders, we want him down there playing so that he can come back up here fresh and ready to go."
Bypassed for the starting assignment on Tuesday was veteran Doug Davis, who has been starting at Omaha. After a pretty good beginning to his season, Davis has struggled of late.
How Yost's pitching rotation sets up after Verdugo's debut on Tuesday is still a bit of a question mark. Lefty Everett Teaford was originally scheduled to start Tuesday, but his emergency relief appearance on Monday necessitated a roster addition. He's listed as the probable starter on Sunday against the Twins.
"We're going to re-adjust the rotation in the next day or two," Yost said. "We've got to get it sorted out. ... It's our last big challenge. You look at the eight guys we put on the field every day and we're real solid."