In 2015, 25-year-old Trevor Rosenthal had just posted a career-low in ERA (2.10) and finished second in baseball with 48 saves. His fastball busted radar guns consistently, blowing the pitch by hitters with ease. He was a pivotal piece on a 100-win St. Louis Cardinals’ team that won the National League Central and was one of the best closers in baseball.

The story, however, took a turn the next season. After a handful of bad outings, Rosenthal was bumped out of the closer role and slid into the set-up spot. His spot was taken by a 33-year-old rookie in Seung-hwan Oh, who the Cardinals had scouted for several years in Asia.

Rosenthal replaced Oh as the closer in July of 2017, but wound up on the disabled list in August with an injury to his ulnar collateral ligament in the right elbow. The injury led to Tommy John surgery, effectively ending his season and time in St. Louis. In November of 2017, the Cardinals released Rosenthal just two years after representing St. Louis in the All-Star game.

Rosenthal would make his return to baseball in 2019. His command, however, would not. In 15 1⁄ 3 innings between Washington and Detroit, the right-hander walked 26 batters, hit four, threw nine wild pitches, and posted a career-high 2.413 WHIP. To start the season, it took him four outings before he recorded a single out (nine hitters faced, four hits, seven runs, four walks).

Rosenthal, who posted a 0.69 ERA in 23 postseason games, entered the offseason with the hopes of another chance to prove his stuff was still there. That opportunity came with the Kansas City Royals, a team shouldering back-to-back 100 loss seasons. Like Rosenthal, the Royals were atop the world in 2015 before stumbling to where they are today.

Now reunited with his former manager in Matheny, Rosenthal is attempting to join the bullpen for a team he grew up watching.

“Hearing the starting lineup and announcing the Kansas City Royals is something I heard for so long growing up,” Rosenthal said during an interview on FSKC. “It’s definitely been surreal. Hopefully I have the chance to put the uniform on and represent the city.”

Trevor Rosenthal on playing for the team he grew up rooting for: "Showing up the first day and shaking hands with Mike Sweeney was a little bit surreal... The fact that he knew my name and knew who I was, was even more surreal." #Royals



TV: FSKC | Stream: FSGO pic.twitter.com/xhcX3LoJny — FOX Sports Kansas City (@FSKansasCity) March 4, 2020

In three outings this spring, Rosenthal has faced 10 hitters and struck out seven of them. The command that hindered him in 2019 hasn’t been an issue, as he hasn’t walked a hitter. Perhaps the most intriguing part of his start has been the velocity that has’t left him since his days with the Cardinals.

Last season, the Royals didn’t throw one pitch over 100 mph. Rosenthal has managed to surpass triple digits in multiple outings already. On Tuesday night against the D-backs, he struck out the side and touched 100 mph on a few fastballs.

Rosenthal gets a strikeout against Calhoun. Hit 100 mph the pitch before. #RoyalsST pic.twitter.com/R8tvSRoawa — Jack Johnson (@JohnyJ_15) March 4, 2020

He gets his second K on a fastball running up and in. Looks good, so far. #RoyalsST pic.twitter.com/lCJy2orDvh — Jack Johnson (@JohnyJ_15) March 4, 2020

Rosenthal strikes out the side. The radar isn’t showing how fast he’s throwing, but it sounds hard. #RoyalsST pic.twitter.com/zCw3zRlR6r — Jack Johnson (@JohnyJ_15) March 4, 2020

Though Rosenthal has been pitching in the league since 2012, he is still just 29 years old. He is currently younger than Jesse Hahn (30), Tim Hill (30), Ian Kennedy (35), Danny Duffy (31), Greg Holland (34) and Mike Montgomery (30).

If the Royals elect to keep Rosenthal when the club breaks camp, there will need to be some roster configuration before he can be added. Barring injuries, Kansas City has three locks for its bullpen in Tim Hill, Scott Barlow, and Ian Kennedy. Jorge Lopez and Glenn Sparkman are likely to get the nod too. Therefore, Rosenthal will battle it out with players such as Holland, Hahn, Kevin McCarthy, Randy Rosario, Josh Staumont, Chance Adams, Kyle Zimmer, and Rule 5 pick Stephen Woods Jr for one of the final 3-4 spots. For Rosenthal to join the roster, the Royals will need to subtract from their 40-man.

It’s been a while since Rosenthal has been completely healthy at the Major League level. If this is what it looks like, the Royals might’ve guessed right on this reclamation project.