KANSAS CITY -- Royals right-hander Kyle Zimmer’s season will not end the way he would have preferred. Regardless, Zimmer’s season will go into the books as a huge success for the 2012 first-round Draft pick.

Zimmer was placed on the injured list on Wednesday, ending his 2020 season after he experienced a “zinger” in his throwing arm while pitching Tuesday night against St. Louis. Zimmer had a similar injury earlier this season and was shut down for more than a week. The Royals listed Zimmer’s injury as right elbow ulnar neuritis, which has caused some numbing in his hand and arm.

The Royals on Wednesday also activated left-hander Mike Montgomery and outfielder Franchy Cordero from the 45-day injured list and recalled right-hander Jakob Junis. The Royals optioned infielder Erick Mejia to their alternate training site and placed outfielder Bubba Starling on the 10-day injured list because of back spasms.

Montgomery made one start this season, on July 27 at Detroit, and left the game with a lat strain.

Zimmer, 29, has experienced a long series of injuries and recoveries over his career but finally made it to the big leagues in 2019, when he stayed healthy for the entire season. This season, Zimmer was focused on taking the next step of being an effective reliever.

Zimmer certainly proved that. He had a 1.57 ERA in 16 games and struck out 26 hitters in 23 innings.

“We’re just being super cautious about him,” Royals manager Mike Matheny said. “Even when he was coming out of the game, he thought he might be OK. But I told him, ‘Hey, what you’ve done this year has just been so, so good. Let’s end with that, build with that.’

“Really, at this point, it’s just risk versus reward.”

Montgomery and Junis will work out of the bullpen but perhaps in slightly different roles.

“They’re both pretty built up,” Matheny said. “We’ll use them wherever we can. I’m excited to watch them. Monty is built up, so he can throw innings for us.”

Junis’ role might be a little different. A starter throughout his career, the Royals’ organization often has debated whether he might be more effective as a reliever in shorter stints. Junis has a 6.94 ERA in six starts this season, the last coming last week in an emergency start for Danny Duffy. Junis was optioned back to the alternate training site after that but can be called up again prior to 10 days because of Zimmer’s injury.

“We’ve talked many times about Jake going just one time through the order,” Matheny said. “This might be an opportunity to take a look at that.”