He's the guy you followed for years while he honed his skills in the Minor Leagues. He was drafted or signed with the label "top of the rotation potential" and regarded as the key to the next wave of talent coming through the organization. Often, he's the bright light you focus on while fast-forwarding in your mind to better times ahead while your team rebuilds.
Future aces are a lifeline of every organization, and every team is likely to have at least one. Let's take a look at who may be anchoring rotations in the American League Central in the years to come:
Indians: Aaron Civale
The Indians were in the process of eliminating an 11 1/2-game deficit in the AL Central last August and spent the month of September trying to earn an AL Wild Card spot. No matter how big of a moment it was for 24-year-old starter Civale – who began the year in Double-A -- his teammates joked his heart rate would be so low that it was unreadable.
Civale made 10 starts in his rookie season and didn’t allow more than two earned runs in an outing until his final start of the year in Chicago. His teammates and manager Terry Francona mentioned seeing similarities between Civale and Corey Kluber, both in stuff and personality, and it’s hard to imagine a better comparison for an up-and-coming starter in the Indians’ organization. Although Shane Bieber seems to have the immediate future locked up as the team’s ace, Civale’s poise, first-season 2.34 ERA, 0.6 homers per nine innings ratio and his Kluber-like stoicism and arsenal give an early indication that a future ace may be in the making. -- Mandy Bell
Royals: Jackson Kowar
To be honest, the Royals’ pipeline of young pitching prospects could produce multiple aces, from Kowar to Brady Singer to Daniel Lynch to Kris Bubic and others. We’ll go with Kowar as our potential ace for now. As one rival scout said during camp, “He probably has the highest ceiling of that group. Once he better commands his curveball, he’ll shoot to the big leagues pretty fast.”
Kowar, 23, was the 33rd overall pick of the 2018 Draft. He has an ace’s frame -- 6-foot-5, 180 pounds -- and velo that can reach the upper 90s, though it sits more around 94-95. Kowar himself said this spring he thought his curveball was improving, and that it would be a fabulous weapon to go with his fastball-changeup base. He threw almost 150 innings last season, splitting time between Class A Advanced and Double-A, demonstrating his endurance. After his promotion to Double-A Northwest Arkansas, he had some expected struggles but finished with a 3.51 ERA with 78 strikeouts and 21 walks in 74 1/3 innings. And several times he showed his ability to dominate at that level, including the night of Aug. 3, when he shut out Tulsa over eight innings, walked none, gave up four hits and struck out six. -- Jeffrey Flanagan
Tigers: Casey Mize
The Tigers' farm system has at least three potential front-line starters in its ranks, including former first-rounder Matt Manning and high-rising Tarik Skubal. Along with Mize, they’re all on MLB Pipeline’s Top 100 Prospects list, forming the foundation of Detroit's retooling effort. What puts Mize on top, at least at this point, is a wealth of big-game experience in SEC baseball at Auburn. He showed in Spring Training a strong ability to work with the pitches he had in a given outing and make adjustments in mid-game. His splitter is a devastating pitch, but his breaking ball is coming along. If Skubal and/or Manning join him in a Justin Verlander-Max Scherzer type of rotation front, the Tigers would be tickled. -- Jason Beck
Twins: Jordan Balazovic
Minnesota currently has the 25-year-old José Berríos locked into its ace role for the foreseeable future, but he'll soon be joined in the Twins' rotation by several other high-upside arms in the coming years. That group is headlined by the 21-year-old Balazovic, who had previously been riding under the radar but turned heads with an elite season between Class A Cedar Rapids and Class A Advanced Fort Myers (2.69 ERA, 129 K, 93 2/3 IP). He rocketed up prospect rankings to No. 86 on MLB Pipeline's overall rankings and No. 4 among the Twins' Top 30, the highest-ranked pitcher on the list.
When the Twins originally drafted Balazovic in the fifth round of the 2016 Draft, he was smaller and less polished because of his cold-weather origins in Mississauga, Ontario, but they felt good about the projectability of the frame, delivery and arm action. Well, he has now grown into that 6-foot-5 frame and cranked his fastball up to where he can sustain velocity in the mid-90s at times. His next challenge will be to test his developing offspeed pitches against hitters in the high Minors. If he continues to harness his fastball and slider in different situations against hitters with better approaches, he should impact the Major Leagues soon and continue the climb to his rising ceiling. -- Do-Hyoung Park
White Sox: Lucas Giolito
Giolito gets the nod among a group of truly viable candidates for the top of the White Sox rotation, if for no other reason than he showed flashes of being an ace in 2019. He has good company in Dylan Cease and Reynaldo López, who are already at the Major League level, and the intimidating Michael Kopech, who is returning from Tommy John surgery. Of those, it was Giolito who proved his value and ability last season, finishing tied for sixth in the American League Cy Young voting.
Giolito, 25, posted a 14-9 record with a 3.41 ERA over 29 starts, striking out 228, walking 57 and yielding just 131 hits over 176 2/3 innings. He recorded road shutouts of Houston and Minnesota, two of the game’s top offenses, and he showed immense improvement and development from 2018, when Giolito had the highest ERA among all qualifying starters.
Giolito made changes to his mechanics, his daily work process from start to start and his mound mindset. And although he was hampered slightly during Spring Training by a mild chest muscle strain near his right rib cage, Giolito believes his game only is going to get better with the work process firmly in place and a major overhaul no longer needed. -- Scott Merkin