Let's keep an eye on Mason Black

If you are sweating what could be the competition for the fifth starter spot in the rotation (emphasis on could), Bailey Falter appeared in Wednesday’s split squad game against the Giants and was…unimpressive. He allowed four runs on nine hits in three innings. Numbers like that are kind of whatever when it comes to spring, but it should be noted he failed to strikeout a single batter. Falter ended up getting just three misses on 27 total swings against the Giants, an 11 percent whiff rate. Falter isn’t a big strikeout guy anyway—he had a 5.8 SO/9 last year—but it’s still something to think about as the Royals set their roster.

I had hoped that Falter, who is out of options, would show something this spring. I don't believe that's happened thus far, and time is running short.

One name in the pitching mix who has caught my attention is newcomer Mason Black. He’s made six Cactus League appearances thus far and limited the opposition to just five hits in eight innings while keeping them off the scoreboard. He’s walked three and whiffed eight.

Black, a right-hander, came to Kansas City this winter from the San Francisco Giants where he was a third-round draft pick back in 2021. Primarily a starter, he was more than a solid prospect, ranking in the top 10 in the Giants organization by Baseball America in each of the last three seasons. He featured a four-seam and two-seam fastballs that lived in the mid 90s range. He also threw a slider with extreme sweeping action that was his swing and miss offering. BA hung a 60 grade on both his fastball and his slider and pegged him as a future back of the rotation innings eater.

After punching out almost 12 batters per nine in Double-A, Black advanced to Triple-A in the second half of 2023. He repeated that level the following season but saw his strikeout rate tumble to 9.2 SO/9 while his walk rate bumped up a bit. Most troubling was the fact he lost velocity off his fastballs.

The sinker had been the primary offering of his fastballs in ’23, but in 2024 he relied much more on his four-seam. Alarmingly, both offerings saw another decrease in velocity, averaging 92 mph.

He found a tick more on the fastballs last season, but it wasn't really enough. Plus, his strikeout rate fell while his walk rate went up. These are some of Mason’s rates at Triple-A over the last three seasons:

That performance, coupled with that velocity decline that he couldn’t fully recover, saw his prospect stock take quite a tumble. Ahead of this spring, is fastball grade was significantly downgraded by BA—to 35.

No wonder the Giants gave up on Black last November and designated him for assignment. The Royals picked him up for Logan Martin before he could hit the open market.

From Baseball America’s 2026 Prospect Handbook:

The root of Black’s woes is a drop in fastball velocity. Black has sat in the mid 90s in the past and threw two fastball variations—a four-seamer and a sinker—in 2025 that both averaged under 93 mph. Black’s once-plus sweeper has also regressed and averaged 82 mph in 2025. Black’s loss of power is mechanical, as he leaks power in his delivery because of his lead leg block. He tends to open up too early and swing his leg past his ideal landing area.

BA now Black ranks as the Royals number 25 prospect and termed him as a “change-of-scenery candidate.” As I’ve written again and again, a pitcher with upside moving to Kansas City is a prime opportunity for the pitching lab headed by Brian Sweeney to unlock that potential. So far this spring, it looks like it’s going quite well. In addition to the overall performance that looks promising, Black has rediscovered some of that heat that went missing, averaging 94 mph on both is four and two-seam offerings.

The Royals have also had Black adjust his pitch distribution. This is how his offerings broke down last year in Triple-A for the Sacramento River Cats:

Once upon a time, the sinker was Black's primary fastball. That's changed since he arrived at the Triple-A level. He would mix in a cutter from time to time, but his main secondary offering was the sweeper.

Here's how he's approached batters in Spring Training thus far:

Black has moved away from the four-seamer this spring to feature his sinker a little more than he has in the recent past. He's also throwing more sliders to play off that sweeper. According to mlb.com, he's even added a curveball to his repitoire, although if that's the case, it's not showing up on the chart above. Through those six outings, you cannot argue against the results.

That said...it's spring. Who knows how sticky these charts and results are?

Manager Matt Quatraro has said that the Royals see Black primarily as a reliever who can provide an occasional spot start. Yet if he can rediscover some of that prospect mojo, could those potential spot starts turn into something more? The only thing that is absolutely certain at this point is the Royals pitching lab continues to yield results. I'm not crazy enough to throw Black into the mix for that fifth spot in the rotation—hell, because of the makeup of the 40-man roster, he remains a longshot to break camp with the major league squad—but I'm intrigued enough by his pedigree and his brief time with the Royals to offer the idea that anything is possible.

The World Baseball Classic continues on Friday with two of the four quarterfinal games. Up first, Korea against the Dominican Republic. That starts at 5:30 CDT and will overlap the first few innings of the second quarterfinal game: Canada against the United States.

This edition of the WBC has not disappointed. From a Team USA manager who is blissfully unaware of math and tie-breaking procedures (and his team’s record and the names of the guys he has in the bullpen) to the pure joy from the Latin American sides to the insane crowds supporting the Asian teams, this tournament has been an absolute blast.

The adopted club of any self-respecting Royals fan—Team Italy—will square off against Puerto Rico on Saturday. To add to the intrigue for us, Seth Lugo will get the start for Puerto Rico against the Azzurri. In an ideal world, Lugo gets through the Team Italy lineup a couple of times unscathed then Vinnie and Jac and company get beaned up after Lugo departs and proceeds to go on a tear.

I do worry that the Azzurri will run out of steam—and caffeine—now that we’ve moved to the bracket portion of the tournament. But as long as the boys have a fresh espresso roast and some hot water, I’m not going to count them out.

Random WBC thought:

Sure, it’s cool that Pasquantino and Caglianone are doing well for the Azzurri, but who can forget the original Royals Team Italy legend, Nicky Lopez? Lopez hit .474/.524/.632 with 7 RBI in 19 at bats in the 2023 WBC.

I actually did forget that.

Michael Wacha has reported back to Royals camp from his time with Team USA. He gets the start on Friday against the Diamondbacks.

Here's how the pitchers will line up for Friday:
Wacha, Noah Cameron, Helcris Olivárez, Shane Panzini

And Saturday:
Ryan Bergert, Daniel Lynch IV, Nick Mears, Jose Cuas, Hunter Patteson

Anne Rogers writes that it was always the plan for Wacha to return from the tournament after the round of pool play. By my count, he's the third Team USA pitcher to leave the squad to return to his club. There may be one or two I'm missing. I think that's a good thing for the Royals and Wacha to do this. The Royals are priority and anything that gets in the way of preparation for the regular season needs to be avoided. Good that Wacha got the experience. Double good that he's back in camp to prepare for his first regular season start.