BOSTON — It’s easy to expect the worst, given the Royals’ recent history, upon learning right-hander Kyle Zimmer, the organization’s first-round pick in June, underwent surgery Thursday to remove “loose bodies” from his elbow.

But club officials insist the procedure was minor and not unexpected.

“Everybody in baseball knew about this prior to the draft,” general manager Dayton Moore said. “It wasn’t anything that caught anyone by surprise. We knew this was going to have to take place at some point in this offseason.”

The procedure was deemed sufficiently minor that Zimmer, 20, made nine minor-league starts after agreeing to a $3 million signing bonus. He went 3-3 with a 2.04 ERA at Rookie Surprise and Class A Kane County.

“We feel very good about the outcome, and expect a full recovery in six to eight weeks,” trainer Nick Kenney said. “We do not anticipate this procedure will alter any of Kyle’s offseason preparation for the 2013 season.”

Moore said Zimmer’s elbow shows no sign of ligament damage. That’s no small thing for an organization that lost four major-league pitchers this season to ligament-reconstruction surgery — a procedure commonly known as Tommy John surgery.

“There were loose bodies,” Moore said, “but they were in a real good place (if you have to have them). His shoulder and his (elbow) ligament are in top form based on all of the scans.”

The Royals, like all clubs, have only limited medical information on players before the draft. Players then undergo a full physical as standard procedure before any financial agreement takes effect.

Even so, the Royals knew Zimmer didn’t pitch last fall because of elbow problems.

“He went out and pitched (this spring),” Moore said. “We put our eyes on him. We were very confident when we selected him knowing full well that he had loose bodies in there, and they’re probably going to have to come out in the next six to 12 months.”

Zimmer’s post-draft physical confirmed the need for a cleanup procedure but were deemed sufficiently minor to allow him to pitch. And he pitched well — striking out 42 and walking just eight while allowing only one home run in 392/3 innings.

“You let him go until you feel you need to go get it,” Moore said. “We knew he could pitch, and he had been pitching with it. We felt it was better to go in and get it done now. The season is winding down, and his team is probably not going to be in the playoffs.”