KANSAS CITY, Mo. -- Yordano Ventura is going back to the minors to try to regain his form from his strong rookie season.
The Kansas City Royals optioned Ventura to Triple-A Omaha on Tuesday after a string of ineffective outings. Ventura, 24, was the team's Opening Day pitcher.
"A lot of times it's good for players to take a step back, so they can take three or four steps forward," manager Ned Yost said.
Ventura, who can run his fastball into triple digits, is 4-7 with a 5.19 ERA in 14 starts this year. He spent nearly a month on the disabled list with inflammation of his ulnar nerve.
Yost acknowledged Ventura is probably feeling some frustration.
"He knows what he's capable of doing," Yost said. "He feels like with his performance a little bit that he's letting everybody down, which is not the case. Everybody believes in him 100 percent."
Left-hander Jason Vargas came off the disabled list and got the start Tuesday night against Pittsburgh, but left with an elbow injury after pitching 1 1/3 scoreless innings.
The Royals said Vargas is dealing with pain on the inside of his elbow. He will have an MRI on Wednesday.
"It was discomfort that caused me to feel like I definitely wasn't going to be able to make any more pitches and be competitive," Vargas told reporters.
Ventura gave up six runs and 10 hits in four-plus innings in Monday night's 10-7 loss to the Pirates. He is 1-3 with a 9.00 ERA in his last four starts.
After going 14-10 with a 3.20 ERA last year and throwing seven scoreless innings to beat San Francisco in Game 6 of the World Series, the Royals signed Ventura to a $23 million, five-year contract at the end of spring training.
"Everybody still knows if we make it back to the World Series he's going to be a big reason why," Yost said. "So just going down and having success for a week or two or three or four or whatever it may be is going to help him in the long run."
Information from The Associated Press was used in this report.