Naoyuki Uwasawa was posted this off-season by the Nippon-Ham Fighters after 9 NPB seasons. He amassed a decent NPB career, racking up 1,118 innings pitched in 173 games and 50 starts.

Here’s a look at his last two seasons with the Fighters:

Season IP ERA Strikeouts Walks K/BB Ratio
2022 152 3.38 127 50 2.7
2023 170 2.96 124 41 3

He compiled a 7.5% walk rate and a modest 20% strikeout rate in his NPB career, with a 18% strikeout rate last season. He uses finesse over power to complement a deep arsenal of pitches, relying more on velo difference and changing of speeds than actual movement.

What does he do well?

As a right-hander, Uwasawa pounds the strike zone with his varied pitches and has been a reliable innings eater since 2020. Since returning from a 2019 injury-shortened season, he has thrown at least 152 innings in the last three seasons. 

He doesn’t have the most potent stuff, but he threw strikes at a 66% strike rate in 2023; all his pitches can be thrown in and out of the zone. With slightly above-average command, he can change speeds and mixes his pitches well. 

He has some promising pitch shapes but teams will buy in on his control and hopefully better command to soak up innings. To be reliable stateside, he must hit his spots.


Uwasawa and NPB posting mate Shōta Imanaga have similar setups and movements in their deliveries. Going straight into a leg lift, Uwasawa brings his knee up to his chest before adjusting down to his belt. 

He then pauses his leg lift and creates counter-rotation in his hips by turning his foot towards the rubber, just like Imanaga. Uwasawa lands with a solid lead leg and his shoulders are level as his right arm gets to a 90-degree angle at foot strike.


At times, Uwasawa deploys a tiny hop off his front foot after ball release, especially on fastballs he throws a little harder, thus showing some athleticism and freedom in how he finishes his movements.


The Arsenal (2023 usage and Average Velocity)

Fastball 44%, 90 MPH

Uwasawa exhibits subpar fastball velocity for MLB and didn’t garner high whiff rates on the pitch in NPB, but was decent in 2023 at 18%. He threw his four-seam at about 41% and his two-seam at 3%. The four-seam is his go-to pitch, as he tries to spot it in different parts of the zone.

His command of the pitch fluctuates between average to above-average. At its very best, it’s a good pitch on the edges of the zone. He has some really interesting fastball characteristics as well.

He can get swings and misses at the top of the zone and creates foul balls in less desirable places. The lack of velocity is worrisome, but with good spin and carry his fastball can still work in MLB. He will most likely have to move away from a heavy fastball reliance though, and can’t leave the pitch in bad spots at its current velocity.

Curveball 14%, 75 mph

Uwasawa’s curve shows good movement when snapped off and he can throw the pitch harder when needed, but he will often use the slower end as a strike-stealer early in counts. The harder version is used more as a chase pitch below the zone against free swingers.

Although he can throw the curveball for a strike, it has his lowest strike rate of any pitch at 62 % compared to his fastball at 68% in 2023. The lower strike rate is due to some of the curves slipping out of his hand and missing the arm side or being spiked in the dirt.

He mainly uses the curve as a change-of-pace and will even mess with timing at points on all his pitches, but the curve is helped by this as he delays his movement down the mound after leg lift. An excellent example of this is an at-bat vs Yakult slugger Munetaka Murakami:


Slider 13%, 81 mph

Uwasawa throws both a sweeper and a harder slider, grouped above when referring to pitch usage. The sweeper sits around 78 mph and the slider can get up to around 84 mph but the shape of the two pitches is key.

At times, Uwasawa’s sweeper gets loopy, morphing into a slurve, with more depth rather than horizontal movement. If he’s able to fix the movement and consistently make it more horizontal away from his curve, that could help the pitch become more distinct.



As with most pitches, more velocity would be nice but even getting the shape consistent would help his slider, sweeper, and curveball separate not only in velocity but also in movement.

Against right-handed batters Uwasawa uses his sweeper and slider as his second-most used pitch. If he’s able to throw more consistent sweepers, then his fastball will play up as a result. 

This plate appearance below against Maikel Franco shows how Uwasawa might mix his pitches in MLB, illustrating how he doesn’t need heavy fastball reliance to pitch to hitters. While this plate appearance ended in a walk, Uwasawa broke off some nice breaking balls and had buy-in from Franco on almost all of them.



Uwasawa will also backdoor his slider to left-handed batters and will even double up or triple up throwing the pitch consecutively. His slider and sweeper generated a modest 25% whiff rate in 2023. Uwasawa is ultimately trying to limit hard contact rather than pick up whiffs. His slider and sweeper accomplished that.


Splitter 13%, 86 mph

Uwasawa’s splitter is probably his best secondary and one that he should use more against left-handed batters. He surrendered only a .490 OPS against his splitter, but it was only his third most-used pitch to lefties, behind his fastball and curve. It might have been a case of Uwasawa relying on more velocity difference to keep the hitter’s timing off of his fastball. 

If he lessens his fastball usage and upticks the splitter (especially to lefty hitters), it will help him stay competitive at the bottom of the zone. With a 53% GB rate on his splitter and a 57% rate on his curveball, those will be his money pitches in terms of keeping the ball on the ground.

His fastball had a meager 30% ground ball rate and a 46% fly ball rate so using his splitter more should help bump up his career-low 40% ground ball rate in 2023. 

Cutter 10%, 87 mph

Uwasawa’s cutter is inconsistent and almost blends with his four-seam, being thrown just as hard at times. If you look at grips and well-thrown ones, the pitch has decent movement but is inconsistent. 

Uwasawa occasionally leaves cutters in the middle of the plate and has them leak back because of minimal cut. This one below is followed by two sliders so the velocity difference saves him: 

When he throws the cutter well though the pitch has decent movement and could fit inside of his arsenal as a weapon against against hitters on both sides of the plate.

Here’s a slider and cutter away from a righty:


Sitting around 87 mph the cutter is a below-average pitch overall, but with more consistency and location there’s still a fit inside of his arsenal.

Changeup 6%, 81 mph

To round out Uwasawa’s deep pitch mix is a changeup that he throws with distinct spin and velocity from his splitter. However, the changeup is a pitch that either needs to be scrapped entirely or needs a drastic overhaul in movement and shape.

While the pitch performed well in 2023, there are just too many instances of the pitch being left in a hittable spot and or up in the zone. The pitch also doesn’t have as much depth as his splitter, and it mainly works because of the velocity difference catching hitters out on their front foot.

There are a lot of examples of Japanese pitchers throwing both a splitter and changeup with far better velocity differential and movement profiles than Uwasawa. Understanding his identity as a finesse pitcher he wants the velo difference if only by about 5 mph. However, slimming down his arsenal, and going with only a changeup or splitter is Uwasawa’s best bet at an effective offspeed pitch in the long run.  

What to Expect

Uwasawa projects as a swingman in MLB with enough durability and control to be given a shot at the back end of a rotation. His four-seam characteristics and splitter have him standing a decent chance at some sort of valuable production for an MLB team, if he consistently hits spots, but the lack of velocity and overall stuff will limit his ceiling to that of a Kyle Gibson-type pitcher.