Prospects. They are the lifeblood of any professional sports organization. Some become success stories while others fade into obscurity. Judging a prospect is an inexact science. With all that being said, it’s therefore noteworthy when a prospect puts together the type of season that starts getting them serious attention. 

Dennis Colleran, 22, was drafted by the Kansas City Royals in the seventh round of the 2024 MLB Amateur Draft. He’s a 6-3, 225lbs right-handed relief pitcher with a blazing fastball and has seen his stock rise considerably after a strong 2025 campaign. It started with Colleran in (Low) Single-A with the Columbia Fireflies and then getting promoted to (High) Single-A with the Quad Cities River Bandits before going to Double-AA with the Northwest Arkansas Naturals. And now, with Spring Training just a few weeks away, the Royals have announced that Colleran will get a taste of Big League Camp as a non-roster invitee. 

Part of his success on the mound is due to his fastball which, according to Baseball America, is the best in Kansas City’s entire system. Given how stacked the Royals are with prospects, that’s saying something. On top of that, Baseball America has Colleran ranked as Kansas City’s 27th-best prospect. 

So, we here at Sportsology.com decided to catch up with the young righty flamethrower to learn more about him. 

*Editor’s Note: Questions and Answers have been lightly edited for clarity.

Question: Let’s start with your childhood, since you grew up in Massachusetts, is it fair to say you were a Boston Red Sox fan?

Colleran: “I was very much a Red Sox fan growing up. I had a photo of (Jason) Varitek (getting) in A-Rod’s face. The headboard of my bed was the Green Monster. I had multiple jerseys and baseball cards of the team. My birthday present most years was tickets to a game, (depending on) where they were in August. My most fond memory was the 2013 World Series. After the 2012 season, where they were pretty bad and the Marathon Bombing, seeing the team accomplish that was special.”

Question: Growing up, which players or pitchers did you try to model your game after?

Colleran: “I always enjoyed Roger Clemens and the intensity he had brought to the game. Craig Kimbrel’s coolness on the mound is what I try and replicate more these days.”

Question: How has your training program evolved as you’ve grown up, especially now that you have been drafted and reached Double-AA?

Colleran: “I have not changed (it) much since (I was)12 years old. I have found what works, tried other things, maybe added a drill or two, but, for the most part, I know what my body does and what it responds to. The most I have changed is a bigger focus in the weight room. I have my typical routine that I stick to and then will add things depending on what I want to work on. The only thing I have really had to do as I move up is shorten it so I am ready faster when my name is called to go in the game.”

Question: As a relief pitcher, you obviously need to be ready at any moment in any game, so how do you deal with those sudden shifts and stay completely locked in?

Colleran: “The season is very long, so being locked in 110% for every single pitch is a guaranteed way to burn out. There is plenty going on in bullpens, whether it’s kids asking for balls or random ‘roadtrip’ games we may play. Having a way to passively keep my mind off the game while still being able to watch and pick up on hitters’ tendencies is what I found to be the best approach. Now, when my name gets called, I have my routine of getting my adrenaline up and I am very thankful we have a great group of guys at every level who help with all of that. Also, it has almost become a Pavlovian response where my heart rate spikes when I get told I’m going into the game.”

Question: Who are some of the coaches who you feel have best helped get you to where you are?

Colleran: “I owe a lot of credit to all the coaches I have had over the years, Coach Hart at my high school. Coach (Mike) Glavine at Northeastern. My current coaches with the Royals. Chris Welch at GBG (Northeast Hawks). But the two who have not only helped my game, but also how I approach my life are Tom Landry, my pitching coach back home and Wayne Griffin, my wrestling coach in middle school and high school. My Father as well, he has helped a lot, not only with baseball but every other facet of my life.”

Question: How would you best describe your pitching arsenal and what kind of pitcher do you consider yourself to be?

Colleran: “I would like to consider myself a power pitcher, but I can produce ground balls when needed. I have a funny story from this past year where, over the announcement speakers, they said if a double play was rolled that inning, then the crowd would get free sandwiches. I pitched around the first guy, who was their best hitter and ended up walking him, then threw sinkers to the next batter, producing a ground ball to the third baseman. (He) ended up turning a double play, so I hope someone was able to capitalize on that.”

Question: What is your personal scouting report on yourself as a pitcher?

Colleran: “My personal scouting report would be, attack early. Once I get ahead, I will never give up a hittable pitch after that.”

Question: As you’ve climbed through the minor leagues, your numbers have gotten better against tougher competition, what do you attribute that to?

Colleran: “I attribute that to the coaching at every level. I came into the season very green, hair on fire every outing, being completely out of control. The coaches at every level have helped me compose myself and then use that composure to attack the hitter.”

Question: Are there any pitches you are currently toying with, potentially adding to your repertoire? And what is the process like for adding a new pitch?

Colleran: “Changeup. Would love to have another weapon against lefties.”

Question: What was your immediate reaction to being drafted by the Royals and how long did it take for that to sink in?

Colleran: “I was very excited. My agent had told me it’s a great place to be for development, as well as a team that every year is competitive at the Major League level. I honestly did not fully feel as if I had been drafted until I came back home from Camp that fall and was away from it.”

Question: Who are some current MLB players whom you try to draw inspiration from? 

Colleran: “George Kirby (due to) his ability to locate, (which is) a part of my game I am always trying to improve. (Aroldis) Chapman as well. His command was much better this year and it paid major dividends.”

Question: If you could choose any current MLB player to face off against, who would it be and why? And if you could choose any former MLB player, who would it be and why?

Colleran: “Mookie Betts. I loved watching him growing up, so being able to pitch against him would be a dream come true. All-time would be Barry Bonds. If I have a chance of striking him out or not, (it) doesn’t matter. I would face him 1,000,000 (times), as if in Purgatory, until I figured him out.”

Question: Aside from the cold weather, what are the challenges you’ve faced growing up in the northeast while attempting to get drafted and now as you climb through the minors?

Colleran: “Weather is a great cop-out many use, but when people down south come up to play in March/April, it becomes an advantage for us. The hardest thing would just be the level of exposure. It’s easy to just get discounted because of where you are from. I can even count the amount of times I have corrected people about where Northeastern is or having it be confused for Northwestern. Or when I guested for a Californian team and people did not know where Massachusetts was on the map. Everything that the Northeast is will be a challenge on the way up, but it becomes a great advantage once you make it there.”