| W | L | ERA | G | GS | SV | IP | SO | WHIP | |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 0 | 0 | 0.00 | 1 | 0 | 0 | 1 | 0 | 1.00 |
| Career Minors | 9 | 0 | 2.85 | 44 | 0 | 3 | 66.1 | 72 | 1.06 |
| G | W-L | ERA | IP | SO | WHIP | |
|---|---|---|---|---|---|---|
| 2025 | 1 | 0-0 | 0.00 | 1 | 0 | 1.00 |
| Career Minors | 44 | 9-0 | 2.85 | 66.1 | 72 | 1.06 |
| Season | Tm | LG | L | W | L | ERA | G | GS | SV | IP | H | R | ER | HR | BB | SO | WHIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | 3 Teams | Minors | 9 | 0 | 2.85 | 44 | 0 | 3 | 66.1 | 36 | 28 | 21 | 4 | 34 | 72 | 1.06 | |
| 2025 | Columbia Fireflies | CAR | A | 4 | 0 | 4.06 | 22 | 0 | 3 | 31.0 | 22 | 20 | 14 | 1 | 19 | 39 | 1.32 |
| 2025 | Quad Cities River Bandits | MID | A+ | 5 | 0 | 1.83 | 21 | 0 | 0 | 34.1 | 14 | 8 | 7 | 3 | 14 | 33 | 0.82 |
| 2025 | Northwest Arkansas Naturals | TEX | AA | 0 | 0 | 0.00 | 1 | 0 | 0 | 1.0 | 0 | 0 | 0 | 0 | 1 | 0 | 1.00 |
| Northwest Arkansas Naturals | TEX | AA | 0 | 0 | 0.00 | 1 | 0 | 0 | 1.0 | 0 | 0 | 0 | 0 | 1 | 0 | 1.00 | |
| Quad Cities River Bandits | MID | A+ | 5 | 0 | 1.83 | 21 | 0 | 0 | 34.1 | 14 | 8 | 7 | 3 | 14 | 33 | 0.82 | |
| Columbia Fireflies | CAR | A | 4 | 0 | 4.06 | 22 | 0 | 3 | 31.0 | 22 | 20 | 14 | 1 | 19 | 39 | 1.32 | |
| Career Minors | 3 Teams | 9 | 0 | 2.85 | 44 | 0 | 3 | 66.1 | 36 | 28 | 21 | 4 | 34 | 72 | 1.06 |
Scouting grades: Fastball: 65 | Slider: 50 | Splitter: 50 | Control: 45 | Overall: 40
Colleran stayed relatively close to home when he chose to go pitch for Mike Glavine at Northeastern University in Boston and was feeling his way through his freshman year as a reliever in 2022 when his elbow blew out and required needed Tommy John surgery. He returned in time to pitch in a pair of summer leagues in 2023, throwing very well in the Cape Cod League, and while his 2024 season was more uneven, he showed off enough arm strength and pure stuff to make him a solid college reliever prospect for the 2024 Draft.
Colleran showed off premium velocity all year at Northeastern, with a fastball that sat consistently in the 96-100 mph range, and showed it off by topping out at 99 mph at the Draft Combine in June, though it’s more straight velo than it is fastball quality. His power 88-91 mph slider can be a true out pitch at times with good hard break to it, and he can even mix in an upper-80s split-change that can kill spin and could give him a third average pitch.
The 6-foot-3 right-hander is a pure bullpen arm who is generally around the strike zone but is much more control than command. Part of the issue with his fastball is hitters get too good a look at it, something that could be corrected with some delivery adjustments at the next level, which area scouts think he’ll be good at adapting to once he enters pro ball.
Scouting grades: Fastball: 70 | Cutter: 60 | Slider: 50 | Control: 40 | Overall: 40
Colleran wasn’t really on a ton of radars entering the 2024 Draft after an inconsistent season at Northeastern. But the Royals were intrigued by his fastball and selected him in the seventh round that summer. He climbed three levels in 2025, ending the year with an inning in Double-A and with a 2.85 ERA across all affiliates. He was especially dominant in High-A Quad Cities, where he made 21 appearances, posted a 1.83 ERA and struck out batters at a 25 percent clip. He also pitched in the Arizona Fall League, where he struck out 11 in 7 2/3 innings.
Colleran’s heater is probably the best in the Royals’ system, given that it sits upper 90s and touched 101 mph in 2025. It’s a plus-plus pitch with really good sink and is hidden well in his delivery with his big leg kick. He throws an above-average 90-91 mph cutter that sometimes registers as a slider depending on the location, as well as an average mid-80s sweeper with big horizontal break. Colleran can get a little wild with high walk rates, but consistency with his secondaries could help with that. He’s focusing on the breaking ball especially, as well as controlling the running game; that big leg kick gives him some deception and power, but it can also get him in trouble.
There’s obviously a lot to like with the velocity on Colleran’s fastball, and he has setup man or closer upside if he can continue to develop the secondary weapons and have better command. The Royals had him in big league camp this spring, so he’s on the radar and could move quickly if he keeps improving.
| Team | Date | Transaction |
|---|---|---|
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03/05/2026 | RHP Dennis Colleran assigned to Kansas City Royals Prospects. |
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01/27/2026 | Kansas City Royals invited non-roster RHP Dennis Colleran to spring training. |
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09/10/2025 | RHP Dennis Colleran assigned to Surprise Saguaros. |
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09/09/2025 | RHP Dennis Colleran assigned to Northwest Arkansas Naturals from Quad Cities River Bandits. |
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06/24/2025 | RHP Dennis Colleran assigned to Quad Cities River Bandits from Columbia Fireflies. |
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04/02/2025 | RHP Dennis Colleran assigned to Columbia Fireflies. |
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07/21/2024 | Kansas City Royals signed RHP Dennis Colleran. |
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06/16/2024 | College Workout activated RHP Dennis Colleran. |
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06/09/2024 | RHP Dennis Colleran assigned to College Workout. |
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04/02/2024 | RHP Dennis Colleran assigned to Chatham Anglers. |
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02/19/2024 | College Workout activated RHP Dennis Colleran. |
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02/16/2024 | RHP Dennis Colleran assigned to Northeastern Huskies. |
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08/23/2023 | RHP Dennis Colleran assigned to College Workout. |
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06/09/2023 | Hyannis Harbor Hawks activated RHP Dennis Colleran. |
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06/09/2023 | Hyannis Harbor Hawks activated RHP Dennis Colleran. |
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02/24/2023 | RHP Dennis Colleran assigned to Northeastern Huskies. |
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02/24/2022 | RHP Dennis Colleran and assigned to Northeastern Huskies. |
