Ben Brown Wins Chicago Cubs' Starting Rotation Battle Over Colin Rea

When I'm watching a Major League Baseball game, sometimes I am watching specifically for the arm up on the bump. Other times, I'm watching for the guys behind the arm, with the pitcher becoming a mere facilitator for the more interesting parts of the game—as the founders of the sport would have had it. It's rarely both. This is the contrast that existed when it came to the Chicago Cubs' final two options for the fifth spot in their rotation.

When spring camp opened, the widely-held assumption was that Javier Assad would get the fifth spot. He'd been solid in his time with the Cubs and, while unspectacular, he provided a certain level of stability. After an oblique injury (one that'll cost him at least a good chunk of April) slowed him in camp, that assumption immediately flipped over to new-but-old face Colin Rea as the guy for the No. 5 slot.

As the exhibition season unfolded, though, the whispers of Ben Brown began to disturb and tickle the East Mesa airwaves. On Tuesday, we got our confirmation: 

Cubs news from Tuesday:

⚾️ Brad Keller has been notified he's made the Cubs.

⚾️ Ben Brown will be then the fifth starter.

⚾️ Vidal Bruján is battling a right elbow issue, he hurt it banging against the wall trying to make a catch over the weekend. IL stint is possible.

— Sahadev Sharma (@sahadevsharma) March 25, 2025

The other two bits of notes there are obviously significant in matters of the Opening Day roster (and gosh, what a bummer about Vidal Bruján's elbow, funny how that worked out). But the news of Brown grabbing the fifth starter job is massive. 

In case you forgot (which is entirely possible, if you live in a western time zone and essentially woke up in the middle of the night to watch the Cubs in Tokyo), we've already seen Brown this season. He followed Shōta Imanaga's four hitless innings in the opener with 2 2/3 frames of his own. The results weren't terrific—four hits, three walks, and three runs allowed—but the stuff was there. 

Brown struck out five Dodger hitters, inducing 14 whiffs in his appearance. The fastball velocity was down from 96.7 in 2024 to 95.6 in the outing, but 13 of the 14 whiffs came on his knuckle-curve (a.k.a. the pitch we actually care about). While we'll have to monitor the velocity, given its importance in allowing Brown to work off and toward his nasty breaking pitch, the fact that the hook was on point is all the encouragement we needed.

That speaks to what makes Brown being in this rotation interesting in the first place. While his fastball was just about average last year, his Stuff+ on the knuckle-curve came in at 124. That's considered to be well above average for a pitch of that variety. Would it be nice to see him develop a third pitch? Sure—especially when we talk about his long-term outlook as a starting pitcher. But the allure of even that particular two-pitch mix isn't something I'm willing to overlook, when you consider the aesthetic appeal of Brown versus that of Rea.

Here is Brown's Baseball Savant percentile distribution: 

And heres Rea's:

Brown's is, obviously, quite imperfect. You'd like to see far less 'hard contact against him and a bit more harnessing of the command. But the velocity and bat-missing you're getting out of him is tantalizing, especially when you're considering him against someone as straightforward as Rea. There's an intrigue and aesthetic appeal that Brown brings, and that is utterly absent with Rea. The veteran righty's greatest strength is control, which is valuable but insufficient in assembling a starter's suite of skills and value sources.

Aside from my own visual preference for watching Brown over Rea, there's a matter of roles here that is entirely logical. Despite the absence of a third pitch, settling Brown into a rotation spot now gives him a bit of stability within his continued development. You keep him on a certain routine, instead of deploying him in a variety of roles as he's attempting to get some longer-term footing. He might fail, for reasons having to do with the limited arsenal or with durability, but it's much easier to switch him to the pen midseason than to stretch him back out if he were to make a move to the pen now.

Rea, meanwhile, is accustomed to this kind of work. In his 2020 work with the Cubs, Rea appeared in nine games while starting two. In 2021 and 2022, with Fukuoka of Nippon Professional Baseball, he combined for 22 starts across 29 appearances. He started 49 of 58 for Milwaukee over the last two campaigns. He's primarily been a starter, but serving as a swingman role (and perhaps as a piggyback option for Brown or Matthew Boyd, at times) will not be unfamiliar or uncomfortable for him.

It's going to be clunky at times for Brown, perhaps deeper into the season than we're comfortable with, but nobody can deny the upside. Nor can they balk at the electricity he has the potential to bring. Between Brown and Rea as your option for the last spot, Brown brings that upside and the aesthetic appeal. Conversely, Rea is exactly the type of boring arm who can ply his trade in work for which he's particularly well-suited. Everybody wins.

But mostly our collective eyeballs. They're the big winners here.