Name: Seth Johnson
Position: RHP
Born: September 19, 1998
Country: United States
Bats/Throws: R/R
Height/Weight: 6’1″ 205lbs
How Acquired:Drafted in the 1st round of the 2019 Draft by the Rays. Traded to the Baltimore Orioles in a 3-team trade with the Houston Astros in August 2022. Traded to the Phillies with Moises Chace for Gregory Soto in July 2024.
Signed: June 12, 2019
Bonus: $1,722,500
Options Remaining: 1
Rule 5 Eligible: 2022
MiLB Free Agency: 2025
Stats
Prospect Rankings
Role: #4 Starter/Multi-Inning Reliever
Risk: Medium – It was a successful first full year back from Tommy John surgery for Johnson, but he still doesn’t fully look like a lock to start. His pitch arsenal plays below the visual and metrics level, and he might lack the ability to really turn over a lineup multiple times.
Summary: Johnson was picked in the 1st round by the Rays in 2019 after pitching only 67.1 innings in college. Then the 2020 season was canceled, and he had Tommy Johnson surgery in 2022 that cut short 3 more years of development. Johnson has only 313.1 pro innings, and 98 of them came in 2024. The Phillies took some of the restrictions off after he came over in the trade for Gregory Soto, but he has yet to really pitch deep games on high pitch counts. It also means that for a 26 year old, he is well behind his age on the developmental curve. His fastball is the most intriguing pitch in his arsenal, averaging about 95 mph with over 18” IVB, but that rise is offset by a less than ideal approach angle given his size, and hitters were able to make contact both in and out of the zone on it. His best pitch after the trade was his slider, which has shorter gyro/cutter movement, and he was able to use it to generate swings and misses both in and out of the zone. He has a big curveball, but in AAA and the majors, hitters hit it every time it was in the zone and almost never chased it. In theory a big breaker should play off of high fastballs, but hitters were clearly able to identify it. He threw a limited number of changeups, and while inconsistent, there were some good flashes. As a starter he will need to develop the changeup and fix what is wrong with the curveball, but as a reliever he could simplify the arsenal to the fastball and slider. He has struggled with command and control when betters have not chased his stuff, and other than the slider he has not had a pitch to compete in the zone. Hopefully, some of the issues will be helped by being another year removed from surgery.
2025 Outlook: Given the Phillies current rotation situation, Johnson won’t be in the competition mix in Spring Training barring an injury. He is 26 and nearing the end of his option years, so while he will definitely start the year in a rotation (probably AAA), there will need to be a conversation about a move to the bullpen at some point.
2025 #15
Role: #4 Starter/Multi-Inning Reliever
Risk: Medium – It was a successful first full year back from Tommy John surgery for Johnson, but he still doesn’t fully look like a lock to start. His pitch arsenal plays below the visual and metrics level, and he might lack the ability to really turn over a lineup multiple times.
Summary: Johnson was picked in the 1st round by the Rays in 2019 after pitching only 67.1 innings in college. Then the 2020 season was canceled, and he had Tommy Johnson surgery in 2022 that cut short 3 more years of development. Johnson has only 313.1 pro innings, and 98 of them came in 2024. The Phillies took some of the restrictions off after he came over in the trade for Gregory Soto, but he has yet to really pitch deep games on high pitch counts. It also means that for a 26 year old, he is well behind his age on the developmental curve. His fastball is the most intriguing pitch in his arsenal, averaging about 95 mph with over 18” IVB, but that rise is offset by a less than ideal approach angle given his size, and hitters were able to make contact both in and out of the zone on it. His best pitch after the trade was his slider, which has shorter gyro/cutter movement, and he was able to use it to generate swings and misses both in and out of the zone. He has a big curveball, but in AAA and the majors, hitters hit it every time it was in the zone and almost never chased it. In theory a big breaker should play off of high fastballs, but hitters were clearly able to identify it. He threw a limited number of changeups, and while inconsistent, there were some good flashes. As a starter he will need to develop the changeup and fix what is wrong with the curveball, but as a reliever he could simplify the arsenal to the fastball and slider. He has struggled with command and control when betters have not chased his stuff, and other than the slider he has not had a pitch to compete in the zone. Hopefully, some of the issues will be helped by being another year removed from surgery.
2025 Outlook: Given the Phillies current rotation situation, Johnson won’t be in the competition mix in Spring Training barring an injury. He is 26 and nearing the end of his option years, so while he will definitely start the year in a rotation (probably AAA), there will need to be a conversation about a move to the bullpen at some point.
Season Reports/Highlights
5.1 IP 5 H 0 R 1 BB 5 K
It wasn’t a huge breakout game for Johnson, nor did he do anything radically different. He threw all 4 of his pitches, but 81% of them were his fastball and slider. It was some of the best velocity we have seen from Johnson as he averaged 95.8 and hit 97.8 twice on the night. He had less rise on the pitch compared to last season, but underlying data indicated he was getting 3-4″ more extension and coming in flatter. His slider was thrown a little softer this year, but came with more drop. While batters made contact with the slider in the zone, he was able to throw it in the zone which allowed him to throw his fastball for chases. Given the shape of the pitch, it is always going to play up better above the zone, and so having a pitch to tunnel off of it that he can compete in the zone with, could be a big step forward. I still think this portends a better fit in the bullpen, but I wrote in the preview that he would need to find some pitch shape and usage improvements, and through one game he has.
2025 Week 1
5.1 IP 5 H 0 R 1 BB 5 K
It wasn’t a huge breakout game for Johnson, nor did he do anything radically different. He threw all 4 of his pitches, but 81% of them were his fastball and slider. It was some of the best velocity we have seen from Johnson as he averaged 95.8 and hit 97.8 twice on the night. He had less rise on the pitch compared to last season, but underlying data indicated he was getting 3-4″ more extension and coming in flatter. His slider was thrown a little softer this year, but came with more drop. While batters made contact with the slider in the zone, he was able to throw it in the zone which allowed him to throw his fastball for chases. Given the shape of the pitch, it is always going to play up better above the zone, and so having a pitch to tunnel off of it that he can compete in the zone with, could be a big step forward. I still think this portends a better fit in the bullpen, but I wrote in the preview that he would need to find some pitch shape and usage improvements, and through one game he has.