Mariners have acquired left-handed pitcher Justus Sheffield, right-handed pitcher Erik Swanson and centerfielder Dom Thompson-Williams from the New York Yankees in exchange for left-handed pitcher James Paxton.


“To add three dynamic athletes who are entering the prime of their respective careers, while also maintaining six seasons of club control for each, is very exciting,” Dipoto said. “Justus Sheffield has an unquestionable prospect pedigree. With a combination of high-end velocity to go along with an advanced slider and a developing changeup, we think Justus has a chance to pitch at the upper portion of our rotation soon. Erik Swanson has performed at every level, combining a mid-90s fastball as well as two effective secondary pitches. At 25 years old, he is just entering the prime years of his career, and we think he will impact our Major League club in the near future. Dom Thompson-Williams is an electric athlete, who we think will move quickly through our minor league system. He brings a powerful left-handed bat, speed on the bases and athleticism in the outfield.”


Sheffield, 22, was ranked by Baseball America as the No. 1 prospect in the Yankees organization following the 2018 season. He has been a top-10 organizational prospect according to Baseball America since making his professional debut in 2014. The 6-foot, 200-pound left-hander spent most of the 2018 season with Triple-A Scranton Wilkes-Barre, where he went 6-4 with a 2.56 ERA (25 ER, 88.0 IP) with 84 strikeouts and 36 walks in 20 games (15 starts). He also made 5 starts with Double-A Trenton, going 1-2 with a 2.25 ERA (7 ER, 28.0 IP) with 39 strikeouts and 14 walks. The native of Tullahoma, TN, made his Major League debut with the Yankees on Sept. 19, 2018 vs. Boston. He was the 6th-youngest player in the American League in 2018, including the 2nd-youngest pitcher. Overall, he made 3 relief appearances with the Yankees last season.


Sheffield was originally selected by Cleveland in the 1st round (31st overall) in the 2014 MLB First-Year Player Draft out of Tullahoma High School (Tullahoma, TN). He made his pro debut with the AZL Indians in 2014, going 3-1 with a 4.79 ERA (11 ER, 20.2 IP) while striking out 29 and walking only 9. Following the season, he was named Cleveland’s No. 4 prospect by Baseball America. In 2015, he was a Midwest League Mid-Season All-Star and finished with a record of 9-4 with a 3.31 ERA (47 ER, 127.2 IP) in 26 starts with Single-A Lake County. He was again the No. 4 prospect in the Indians organization by Baseball America after the season.


Midway through the 2016 season, he was acquired by New York-AL from Cleveland along with J.P. Feyereisen (rhp), Clint Frazier (of) and Ben Heller (rhp) in exchange for Andrew Miller (lhp). In 2016, he made stops with High-A Lynchburg (CLE), High-A Tampa (NYY) and Double-A Trenton, combining to go 10-6 with a 3.09 ERA (43 ER, 125.1 IP) with 129 strikeouts and 53 walks in 25 starts. He was a Carolina League Mid-Season All-Star while with the Cleveland organization. He entered the 2017 season as the No. 7 prospect in the Yankees system according to Baseball America. In 2017, he appeared primarily with Double-A Trenton, earning a spot on the Eastern League Mid-Season All-Star Team while posting a record of 7-6 with a 3.18 ERA (33 ER, 93.1 IP) with 82 strikeouts and 33 walks in 17 starts. He also made 2 starts with the GCL Yankees. Following the season, he ascended to the No. 3 prospect in the Yankees organization by Baseball America, as well as the No. 41 overall prospect in baseball.


Over 5 minor league seasons in the Cleveland (2014-16) and Yankees (2016-18) organizations, Sheffield has a career record of 36-24 with a 3.08 ERA (167 ER, 487.2 IP) with 507 strikeouts and 184 walks in 103 career games (94 starts). He has an overall strikeout-to-walk ratio of 2.76 (507 K, 184 BB) in the minors while averaging 9.36 strikeouts-per-9.0-innings (507 K, 487.2 IP). In his minor league career, he has allowed only 0.59 home-runs-per-9.0-innings (32 HR, 487.2 IP).


Swanson, 25, split the 2018 season between Double-A Trenton and Triple-A Scranton/Wilkes-Barre, going 8-2 with a 2.58 ERA (33 ER, 115.0 IP) in 22 games, 20 starts. The 6-foot-3, 220-pound right-handed pitcher averaged 10.41 strikeouts per 9.0 innings (133 SO, 115.0 IP), while limiting opponents to a .204 (85×416) opponents’ batting average. He allowed 3 runs or fewer in 17 of his 20 starts, including 7 straight starts allowing 1 run or fewer from April 10-May 15. During this 7-game stretch, he went 4-0 with a 0.46 ERA (2 ER, 39.0 IP) while walking 14 and striking out 49. Swanson spent two stints on the disabled list last season with a right groin strain, June 13-July 14 and Sept. 8-24. He also made 2 starts on a rehabilitation assignment with Short-Season-A Staten Island, July 5-12, going 0-0 with a 4.05 ERA (3 ER, 6.2 IP).


In 5 minor league seasons with Texas (2014-16) and New York-AL (2016-18), Swanson is 23-12 with 2 saves and a 3.35 ERA (133 ER, 357.0 IP) in 93 games, 59 starts.  The native of Cincinnati, OH, was originally selected by the Rangers in the 8th round of the 2014 MLB First-Year Player Draft out of Iowa Western Community College. He was acquired by the Yankees from the Rangers along with right-handed pitchers Dillon Tate and Nick Green in exchange for outfielder Carlos Beltran on Aug. 1, 2016.


Thompson-Williams, 23, spent most of 2018 with High-A Tampa, batting .290 (96×331) with 56 runs, 16 doubles, 4 triples, 17 home runs, 65 RBI and 17 stolen bases in 90 games. The left-handed hitting outfielder also appeared in 10 games with Single-A Charleston, batting .378 (14×37) with 7 runs, 1 double, 5 home runs and 9 RBI. He was Florida State League Player of the Month for August after leading the league in extra-base hits (16), total bases (71), RBI (30) and OPS (1.121).


In parts of 3 minor league seasons in the Yankees organization, the 6-foot, 190-pounder is a career .270 (212×784) hitter with 34 doubles, 5 triples, 28 home runs, 118 RBI and 44 stolen bases in 220 games. Thompson-Williams was selected by the Yankees in the 5th round of the 2016 First-Year Player Draft. He was also selected by St. Louis in the 19th round of the 2014 MLB First-Year Player Draft, but did not sign. He spent 2 seasons (2014-15) at Iowa Western Community College before transferring to the University of South Carolina (2016), where he hit .321 (77×240) with 58 runs, 17 doubles, 3 triples, 8 home runs and 41 RBI in 64 games.


Paxton, 30, made 28 starts with the Mariners in 2018, despite 2 stints on the disabled list, going 11-6 with a 3.76 ERA (67 ER, 160.1 IP) with 208 strikeouts and 42 walks. The 6-foot-4, 227-pound left-hander ranked 9th in the American League in strikeouts, and among AL pitchers with at least 160.0 innings pitched last season, he was 3rd in K/9.0 IP (11.68), 4th in K/BB ratio (4.95), 7th in WHIP (1.10/42 BB, 134 H, 160.1 IP) and 9th in opponents’ average against (.224/134×598). The native of Ladner, British Columbia, Canada threw the 6th no-hitter in club history on May 8 at Toronto.


Selected by the Mariners in the 4th round of the 2010 MLB First-Year Player Draft, Paxton made his Major League debut with Seattle on Sept. 7, 2013 vs. Tampa Bay. In parts of 6 Major League seasons with the Mariners (2013-18), he compiled a record of 41-26 with a 3.42 ERA (221 ER, 582.1 IP) with 617 strikeouts and 168 walks in 102 starts. He has made 7 trips to the disabled list in the last 4 seasons.