Sometimes you just have to give credit where credit is due. The Seattle Mariners scouting department should stand up and take a bow for seeing something in Bryan Woo that many other teams did not.

Woo has been a huge boost to a Seattle pitching staff that has suffered through a series of injuries this season. But very few people outside of Seattle fans probably knew who Woo was before the start of the year.

Woo was drafted in the sixth round of the 2021 draft out of Cal Poly. Being drafted in the sixth round isn’t bad, but the Mariners took him despite undergoing Tommy John surgery that year, and with Woo posting a career 6.36 ERA and 1.731 WHIP in 69.1 innings at Cal Poly, appearing in 31 games and making six starts.

While he had a horrid ERA and WHIP, Woo had a great K/9 rate of 11.6. However, he also had a BB/9 rate of 4.0 and allowed 89 hits in those 69.1 innings of work.

But those numbers and the fact Woo was coming off TJ surgery did not scare away Seattle.


2019-21 NCAA 4-7 25-25 69.1 31 89 6.36 1.731 11.6
2022 RK|A|A+ 1-4 16-16 57.0 22 84 4.11 1.316 13.3
2023 AA 3-2 9-9 44.0 12 59 2.05 0.886 12.1
2023 Mariners 4-4 16-16 80.2 26 82 3.90 1.165 9.1

Returning to the diamond on June of 2022, Woo didn’t exactly set the world on fire. In 57 innings, he had a 4.11 ERA and 1.316 WHIP. The good news is he did have a great 13.3 K/9 rate while his walk rate was 3.5%, not horrible for a player who went more than a year before pitching in a competitive game.

Then came his time in the Arizona Fall League. Pitching for Peoria, Woo opened lots of eyes with his performance. He allowed only five hits and four walks in 10.2 innings while striking out 16 while posting a 0.84 ERA and a 0.844 WHIP.


Entering the 2023 season, Bryan Woo wanted to show his AFL success wasn’t a fluke. It wasn’t.

Making nine starts at Double-A, Woo had a 2.05 ERA and 1.886 WHIP with a strikeout rate of 12.1/9 innings while his walk rate fell to 2.5/9 innings. In his 44 innings of work, he allowed only 27 hits while walking 12 and fanning 59 batters.

Woo was Seattle’s Minor League Pitcher of the Month in both April and May, which makes sense as he held opponents to a .174/.256/.232 slash line before being recalled to the majors in June.


The secret to his success is both his four-seam fastball and two-seamer. Against Woo’s four-seamer, which averages 95.1 mph, opposing batters have only a .220 batting average with a 30.4 Whiff%. Making the four-seamer so successful is the command Woo has of the pitch, constantly hitting his spots to his glove side, or inside to left-handed pitchers.

Meanwhile, batters have only a .207 batting average with a .337 slugging percentage and 21.0 Whiff % against his two-seamer, which averages 94.9 mph. And the two-seamer is a pitch that he introduced this year.

But the 6-foot-2 right-handed hurler doesn’t rely solely on his fastball. He throws a cutter that has a 35.6 Whiff% and a .229 average against and .257 slugging percentage as well as a slider that is limiting hitters to a .242 average and 32.2 Whiff%.


As you can see from the chart above, Woo (ranked as the sixth-best prospect in the Seattle system by MLB Pipeline when he was recalled) is nearly above average across the board in a host of pitching categories. His average exit velocity ranks in the 85th percentile while his hard-hit percentage ranks in the 89th percentile.

And those percentages have only gotten better as the season has progressed.


In his first month in the big leagues, Bryan Woo didn’t look like the pitcher he was the first two months in the minors of the pitcher he has been since the start of August.

In five June starts and 22.2 innings, Woo had a 4.37 ERA and 1.235 WHIP. He struggled even more in July. In 26.1 innings over five starts, Woo had a 5.47 ERA and 1.291 WHIP while allowing five home runs. even more alarming was the fact that his strikeout rate dropped from 12.7/9 in June to 7.5/9 in July.

Despite his poor performance, the Mariners stuck with Woo, and Seattle fans are happy they did. In three August starts, Woo posted a 1.69 ERA and 0.875 WHIP. Opposing hitters had a measly .182/.237/.200 slash line against Woo while striking out 14 times. And he has continued to pitch well this month. In three starts he is 2-1 with a 2.87 ERA and 1.149 WHIP.


Despite the success Bryan Woo has had the last two months, opposing fantasy players aren’t really jumping onto the Woo bandwagon. He is owned in only 48% of Yahoo leagues and 19% of ESPN leagues.

I obviously think those numbers should be higher. Yes, he has a very ugly track record from his college years and first year in pro ball. But he is now fully recovered from Tommy John surgery and has posted outstanding numbers this year – first during his two-month stint in the minors and now over the last two months.

He will hit a few bumps in the road, but I like what he brings to the table and I think he would be a solid player to have on your dynasty team.