With the Seattle Mariners pulling the trigger last night on the trade of LHP James Paxton to the New York Yankees, the value of the return on this trade is already being debated.
The Mariners received LHP Justus Sheffield, RHP Erik Swanson, and OF Dom Thompson-Williams for Paxton. Sheffield is a name most any prospect tracker would know, and Swanson was outstanding in Class-AA Trenton (5-0, 0.42 ERA, 55 K, 15 BB in 42 2/3 IP) and solid in Class-AAA Scranton/Wilkes-Barre (3.86 ERA, 14 BB, 78 K in 72 1/3 IP), and looks destined for the Seattle ‘pen in 2019.
The third player is drawing little attention, comparatively, but Thompson-Williams is worth a second look for those who see him as an afterthought.
A highly-athletic outfielder with a tool set centered around a power-speed combo, Thompson-Williams finally saw that power express itself in 2018 when he swatted 22 homers in 100 games between the Low-A Charleston RiverDogs (.378, 5 HR, 9 RBI in 10 games) and High-A Tampa Tarpons (.290, 16 doubles, 17 HR, 65 RBI, .872 OPS in 90 games). His wRC+ of 147 with Tampa was reflective of his previous season totals (113 w/ Staten Island in 2016 and 132 w/ the same team in 2017), discounting his first appearance with the RiverDogs in 2017, an abortive wRC+ of 47 in 23 games being the result.
His K% of 25.3 is indicative of his continuing adjustment to higher velocities, as he had developed a reputation in the past for hitting off-speed pitches at a more frequent clip than top-shelf fastballs. He has the strength and hand-eye coordination to improve in this area, and he has certainly made progress, though how he will function in Double-A remains to be seen. If he can improve on his 8.3% BB rate, perhaps boosting it to double-digit territory, at least he can offset those empty outs.
One interesting stat: his 20.2% HR/FB rate. His IFFB% dropped to a career-low 10.7%, and his FB% peaked to a new career-high 36.1%. He is still more of a ground-ball hitter (1.19 GB/FB ratio in 2018; 1.32 in 2017 w/ Charleston; 1.93 w/ Staten Island), and the sudden home-run pop appears to be more a result of simply squaring up pitches more frequently and turning on fastballs with a bit more confidence (see above).
He’s definitely a pull hitter, going to right 46.6% of the time, and this may be where his home-run power primarily resides as he matures. He showed little in the way of a platoon split, actually hitting lefties slightly better, albeit in only 96 at-bats. He recorded a .313 BA vs. LHP, .281 vs. RHP in his 90 games with Tampa. He’s often able to open up on middle-in pitches quickly, taking away the low-and-in weakness typically shared by left-handed batters.
His above-average-to-plus speed makes him a true threat on the base-paths. It also makes him a highlight waiting to happen in the outfield, at times. He has worked at refining his routes in the field, focusing more on efficiency as opposed to using his speed to compensate. He has the speed to play center, and also spent 27 games in left, as well as 16 games in right in 2018, handling all three positions well enough to be at least a dependable reserve.
What the Mariners have (for the moment; tomorrow, he could be somewhere else) is a strong and athletic outfielder who should have the developing skills and natural ability to become a reserve, one with more to offer than the average, glove-first sub. If he can deal with the high-90’s heat he’s going to see literally every game in the higher levels of pro ball, even if he struggles from time to time, he could be a good part-time starter who can pop the occasional homer and record double-digit steals along the way. This is especially true for a team in a full rebuild, which the M’s are destined to be in the coming months.