Sanchez was designated for assignment on Tuesday; he and the Royals have 10 days to determine his fate.
The Royals also called up left-hander Ryan Verdugo, obtained from San Francisco in the same trade with Sanchez for Melky Cabera, from Triple-A Omaha to start Tuesday night's game against the Seattle Mariners, his Major League debut. In addition, the Royals recalled right-hander Vin Mazzaro from Omaha and optioned outfielder Jason Bourgeois to the Triple-A club.
Sanchez has had many rough outings since joining the Royals, but the worst came on Monday night against Seattle when the first five Mariners in the first inning scored via two home runs. Sanchez also gave up a two-run triple in the second inning. In the space of 50 pitches, the lefty got four outs, while giving up seven hits, one walk and seven runs.
That was the final straw.
"The results just weren't very good," general manager Dayton Moore said. "It was just outing to outing, we kept evaluating it and we just felt a change is required at this point."
Just who will take Sanchez's rotation spot remained an open question. Manager Ned Yost wants to solidify his plans in the next couple of days.
Sanchez's last outing jumped his ERA to 7.76 and dropped his record to 1-6. In 53 1/3 innings, he'd given up 65 hits including eight homers and 44 walks. He also hit five batters and made four wild pitches.
The Royals have 10 days in which to trade or release Sanchez or, if he clears waivers, to offer him an option assignment to the Minors. So there's still the possibility that Sanchez will remain in the Royals' organization.
"I hope he does, because we still believe in him," Moore said. "He's a terrific citizen who works extremely hard. Body language is what it is and I can understand some of the things that maybe frustrate some of our fan base and some other people, but knowing the person ... I'd love to have him in Omaha if he so desired and try to work through some things. Put it this way: If he were released by another organization, we would be pursuing him to go to Triple-A."
Moore's body language reference stemmed from public criticism that Sanchez often looked as if he didn't care.
Sanchez, as a veteran of five-plus Major League seasons, also could elect to become a free agent, but Yost also would like to see him stay in the organization.
"We designated him and that gives us 10 days to trade him, but he also has an option and, if he agrees, he can go to Triple-A with us, which I'd personally like to see him do," Yost said. "Because it's still there, his stuff's still there."
Sanchez was not at the stadium when the move was announced, so his reaction had to come second hand.
"Heart-broken," Yost said. "But he understood, I think."
"He's very remorseful that this didn't work out," Moore said, "and he's got to sort through some emotions right now."
The Royals, seeking to strengthen their rotation, obtained Sanchez and Verdugo in a winter trade with the Giants for Cabrera. Both Sanchez and Cabrera were coming up on their free-agent years. Cabrera has enhanced his marketability with a terrific season, including the All-Star Game MVP Award while Sanchez foundered.
"There have been examples over the years of guys going to different teams for the first time and putting a lot of pressure on themselves," Yost said. "He was with the Giants, immersed in a real good rotation where he wasn't the No. 1 guy, came over here and felt a lot of pressure to the a top-of-the-rotation type guy and it just compounded on him."
Sanchez won his first Royals start on April 8, pitching five innings of a 7-3 win over the Angels. But he hadn't won since. After making five more starts, Sanchez went on the disabled list for more than a month with biceps tendinitis in his pitching arm. After his return on June 13, he made six starts with a 0-4 record.
"He gave us a great effort and he's a terrific human being," Moore said. "I know he was wearing it internally a great deal, it was very bothersome for him and the pressure just continued to mount. He gave us everything he had ... he cares a great deal regardless of what his body language may be perceived. It's just one of those things that just didn't work out."
Sanchez last experienced great success in 2010 as he helped the Giants in their march to the World Series title with a 13-9 record and 3.07 ERA in 34 regular season games. That season, Sanchez racked up 205 strikeouts in 193 1/3 innings, but also led the National League with 96 walks.
His history also includes a no-hitter against San Diego on July 10, 2009, when he struck out 11 and walked none. Only an eighth-inning error prevented a perfect game.
Last year, Sanchez started just 19 games for the Giants, missing most of the second half with left biceps tendinitis and then a severe left ankle sprain. His season ended on Aug. 16, 2011, with a 4-7 record and 4.26 ERA.
Sanchez, 29, signed a one-year contract for $5.6 million with the Royals last winter, avoiding salary arbitration. He has a Major League record of 39-52 with a 4.50 ERA in 186 games (130 starts).
Fellow pitcher Everett Teaford said that Sanchez was always a good teammate.
"Hopefully he gets it going, because deep down he cares about how he pitches," Teaford said.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.