ANAHEIM — When it comes to debut outings, Jackson Kowar’s MLB debut was one that did not go as imagined.

Kowar, the Royals’ No. 4 prospect according to MLB Pipeline, began his night by getting Justin Upton out on a slow ground ball to first base, but struggled from then on in the Royals’ 8-3 loss to the Angels at Angel Stadium on Monday.

He walked Shohei Ohtani, allowed a single to Anthony Rendon, walked Jared Walsh and gave up a single to Max Stassi before recording his second and final out.

After retiring José Iglesias on a groundout and allowing a single to Juan Lagares, Royals manager Mike Matheny made the walk from the visitor’s dugout to the mound to remove Kowar and replace him with veteran Ervin Santana after just two-thirds of an inning.

The rookie showed off his sharp fastball that consistently hovered around 95-96 mph and at times touched 97. His command, however, was sporadic. He threw 39 pitches (21 strikes), including three wild pitches, and couldn’t get any of his 16 changeups over the plate for a called strike. Only three of his pitches were called strikes.

The highly touted prospect turned heads in the Minors before getting the call to the big leagues. He went 5-0 with Triple-A Omaha and led qualified Triple-A pitchers in ERA (0.85) and batting average allowed (.165) while ranking second in WHIP (0.88) through his first six starts.