CLEVELAND -- On Sunday evening, as the Royals took off for Cleveland to begin their final road trip of the season, Dylan Coleman was given his first "Welcome to the big leagues" moment.

The Royals right-hander, who was selected from Triple-A Omaha on Monday ahead of Kansas City's doubleheader against the Indians, was handed an inflatable alien costume and told to wear it.

Welcome to rookie dress up day.

"Tough draw to come in on that day, but it was fun," Coleman said at Progressive Field on Monday.

Coleman wouldn't trade the moment, though, because it means he's in the big leagues. The 25-year-old from Potosi, Mo., was drafted by the Padres out of Missouri State and came to the Royals last season in the Trevor Rosenthal trade. The first prospect the Royals got in that trade was Edward Olivares.

On Nov. 5, 2020, Coleman became the player to be named later. He had grown up watching Rosenthal pitch for the Cardinals. Now their names will always be linked.

"Any game I would go to would be the Cardinals, and then obviously growing up and watching him -- I've always wanted to be a high velo guy," Coleman said. "He was always throwing hard. And then to get traded for him, it was cool, honestly."

From player to be named later to entering the Royals' mid-season prospect rankings at No. 29 on MLB Pipeline, Coleman's career has gone from being an intriguing prospect in the Draft to falling off scouting reports because of a drop in velocity -- to dressing up as an alien headed to Cleveland with the Royals.

"I don't think it's truly hit me yet, like, 'What's going on?' But pulling up to K.C. yesterday, seeing the stadium, and then walking out here earlier, it's starting to get there," Coleman said. "Starting to get some jitters and nerves, but I think it's part of it."

Coleman's journey to professional baseball began at Missouri State, where he was hitting 97 mph. That potential intrigued a number of scouts, including the Royals. The Padres got to him first, in the fourth round in the 2018 Draft. He posted a 3.18 ERA in both 2018 and '19 in the Padres organization, and the numbers looked good -- but his velocity dropped considerably. It tumbled from 97 mph down to the low-90s before settling in the upper 80s. Scouts noticed, and reports reflected it.

Coleman went searching for answers to the velocity drop. He wasn't sure how it had happened but knew he needed to fix it. In 2020, Coleman crossed paths with his trainer from St. Louis, an hour north of Coleman's hometown. He had met Forrest Herrmann while in college and worked with Herrmann at Premier Pitching Performance (P3) in St. Louis before Herrmann became a Minor League pitching coach for the Reds.

Last offseason, Herrmann had Coleman work on different drills during his side sessions to pinpoint momentum with his arm action. They adjusted his throwing program. As the offseason continued, Coleman's velocity increased. It now sits at 97-100 mph.

"It was just that, 'Wow,' moment kind of thing," Coleman said. "From there on, everything clicked."

With his velocity back where he wanted it, Coleman showed up to Spring Training in the Royals' system and worked on his slider. He worked with Double-A Northwest Arkansas pitching coach Derrick Lewis on a new grip that upped the slider's velocity to 88 mph, and it became more of a power slider than the curveball shape it had been before.

With a big fastball and biting slider, the Royals now have a potential back-end bullpen arm in Coleman. The numbers this season back that up: He has a 3.28 ERA in 45 games between Double-A and Triple-A, striking out 93 in 57 2/3 innings. Over the last six appearances in Omaha, Coleman has allowed just five baserunners in 7 2/3 innings -- striking out 14 and walking three in that span.

As Coleman talked, he rarely took his eyes off the mound at Progressive Field. He's envisioned himself out there, he acknowledged, but never more than a few moments. Twice this season, he thought he was ready for the next level, and both times, his outing the next day was one to forget.

So he focused on "dominating each day." And when the moment comes, he'll be ready.

"The new scenery, almost like a fresh start, it was what I needed," Coleman said about coming over to the Royals. "The whole mindset was a new beginning, and here we are. It's just exciting."