Outfielder Brett Callahan has been an interesting though unheralded Detroit Tigers’ prospect for a few years now. Initially, he caught our eye with good pull power and a strong throwing arm. Over the last few seasons, his complete game has really come together. After a modest start in his Double-A debut this spring, he’sreally caught fire over the last month. Callahan has a strong enough all-around game, the kind of the Tigers sorely lack in their outfield, that if he even develops into an average
hitter he’s going to be a pretty valuable. His speed and defensive ability lower the bar a bit, and at the same time the 24-year-old is now tearing up the Eastern League pretty well.
The Tigers selected Callahan in the 13th round of the 2023 draft. He played his college ball at St. Joseph’s University, a relatively small Jesuit run private college near Philadelphia. The Tigers have seemingly scouted smaller colleges, and the northeast in general, more than most MLB teams in recent years, and it has paid some dividends. They landed Callahan for just $197,500, and got a very good deal.
The left-handed hitter posted a solid full season debut in Single-A ball in 2024. His numbers didn’t leap off the page, and for a relative unknown on draft day, it takes a lot to get some attention. It didn’t help that a dislocated finger and a leg injury shortened his season. Still, he hit seven homers in 62 games with an 8.8 percent walk rate and an acceptable 21.2 percent strikeout rate, slashing .276/359/.439 while stealing 20 bases. That, combined with the built-in loft and pull tendencies in his swing got our attention here.
A quad injury in 2025 made for another somewhat abbreviated campaign, but he advanced to High-A West Michigan and remained productive despite being a little more limited in the speed department. His strikeout and walk rates moved just slightly in the wrong directions, but he still hit nine homers in 55 games, slashing .259/.316/.473, good for a 123 wRC+ and was clearly slowed by the injury a while.
That kept him enough on the radar that we ranked him 26th in the system with a 40+ grade over this past offseason. However, he still was unnoticed by most of the national prospect sites. His “pedigree” as it were, along with the injuries and an aggressive approach at the plate despite decent K-BB numbers, just never got him on the radar.
Things changed this spring, as Callahan made a few trips over to the major league side of spring training camp with the Tigers and did damage. Clearly healthy, running well, and with a little more muscle on his 6’0” 195 pound frame, Callahan launched a pair of homers in Grapefruit League action, as he and fellow Erie SeaWolves hitter, 2B/SS John Peck, both made an impression as more mature, physical players showing some signs of breaking out into really legitimate prospect territory.
That impression has proved accurate. Callahan now has 12 homers in 55 games, and while UPMC Park is a bit of a launching pad, the exit velocities have been strong. Even more importantly, Callahan has improved his plate discipline, walking 13.9 percent of the time against a very reasonable 20 percent strikeout rate despite the difficulty of the toughest leap in competition prospects face until they hit the big leagues. He’s hitting .278/.388/.527 and has collected 20 stolen bases. The Double-A rule allowing only one disengagement, rather than two as in the majors, has probably helped with that as fellow SeaWolves Peyton Graham and Seth Stephenson are both racking up huge stolen base totals as well, but Callahan has above average to plus speed, and that translates to covering quite a bit of ground in the outfield as well.
What really ties this all together is that Callahan isn’t just some wild swinging masher bound to flame out in Triple-A or the bigs. He’s really put together a much more disciplined approach and is chasing less and less, despite the fact that he will absolutely take his hacks when he sees something he likes. Despite the aggression, his swing is fairly compact as well, so he’s not as vulnerable to getting started too early the way many big swinging left-handed power hitters are. Even better, Callahan’s good speed and excellent arm strength and accuracy translate into a future as a pretty good right fielder. Even as a future role player, he has the well-rounded game to contribute even during cold stretches at the plate.
I’ve jokingly referred to Callahan as Kerry Carpenter 2.0 for a while now, and though he’s unlikely to be quite as dangerous a hitter as Carpenter at the major league level, the defense and base stealing ability give him dimensions to his game that Carpenter has never had to offer. And possibly the run he’s on says that a true breakout is underway that could give the Tigers the whole package.
Callahan has mashed five home runs over his last eight games alone, striking out just four times in that span against six walks. He’s trimmed his swinging strike rate down 2.5 percent to a pretty manageable 13.5 percent despite the tough leap in competition this season. His progress now bears close watch, as he’s angling toward a promotion to Triple-A Toledo sometime around the All-Star break, when the Tigers usually do most of their midseason promotions.
As you might expect for a left-handed power hitter with loft in his swing and pull tendencies, Callahan does struggle somewhat with left-handed pitching. He’s getting his first taste of consistently good left-handed pitchers at Double-A, and he’s holding his own with a .786 OPS, but his .983 OPS against right-handed pitching speaks to a likely future role as the strong side of a right field platoon.
Callahan holds a 1.274 OPS overall in June, so he is clearly on one heck of a tear. Whether he can sustain it into July remains to be seen, but he has clearly improved quite a bit. He’s not going to crash the gates and end up on top 100 lists this offseason unless he keeps it going the rest of the year, but all signs point to a developing hitter who already has the speed, arm strength, and defensive chops to be a valuable all-around contributor.
If you like an underdog story in the vein of Carpenter, or Keider Montero, Brett Callahan is your guy right now. His chase and strikeout rates are fine for the Double-A level, but he projects to a low average hitter who walks some and ideally hits for average power. With his all-around game, including the ability to play some center field, that’s enough to make him an average player. And if it all comes together with the bat Tigers fans are going to be very pleased with the results.
