"The Commissioner's Office has taken him off the field for now," Royals general manager Dayton Moore said Friday.
Hosmer agreed to a $6 million signing bonus on Aug. 15, signed the contract, reported to Kansas City on Aug. 22 for a news conference and workout and then went to Idaho Falls.
Last Wednesday the Pirates revealed a dispute over the signing of third baseman Pedro Alvarez, the No. 2 overall pick in the June 5 First-Year Player Draft. Alvarez and Hosmer, the No. 3 overall choice by the Royals, are represented by agent Scott Boras.
According to a Pirates statement, Alvarez also agreed to a $6 million bonus, but he has refused to report and sign a contract because he is seeking more money. Later on Wednesday, the Players Association filed a grievance questioning a deadline extension that it contends the Commissioner's Office granted beyond the midnight ET signing deadline on Aug. 15.
Hosmer's agreement with the Royals was mentioned in both documents.
A hearing will be held on the matter, and Sept. 10 has been mentioned as a possible date for it.
Does all of this jeopardize Hosmer's deal with the Royals?
"I don't know. I have no idea," Moore said. "I don't think so, but like I've said, we had an agreement and the terms were submitted in a timely manner. That's the situation, and our guy's being brought into this and we're just dealing with it."
In Hosmer's three games for the Idaho Falls Chukars, he was 4-for-11 (.364) with two doubles and two RBIs. The Royals were notified on Thursday morning that Hosmer should not play again until the matter is resolved. That's not likely to happen before the Chukars' season ends on Sept. 5.
J.J. Picollo, the Royals' assistant general manager and director of player personnel, said Hosmer still is with the club and might be sent to Surprise, Ariz., to continue workouts.
"The guy you've got to feel for a little bit is the kid," Picollo said. "He's put in the middle of something, and all he really cares about in the end is playing baseball. To not be able to do the thing that he wants to do is just frustrating."
When the matter is settled, the next logical step for Hosmer would be playing in the Arizona instructional league.
Meantime, Moore was at the Royals' game in Detroit, and he repeated that the organization made a valid agreement with Hosmer.
Could he give Royals fans any assurance the club will retain its prize Draft choice?
"Just tell them to lose sleep like I am," Moore said. "I don't know."