NATIONAL HARBOR, MD -- Seattle Mariners Executive Vice President & General Manager of Baseball Operations Jerry Dipoto announced today from the Major League Baseball Winter Meetings that the club has acquired right-handed pitcher Chris Heston from San Francisco in exchange for a player to be named later. To make room on the Mariners Major League 40-man roster, infielder/outfielder Richie Shaffer has been designated for assignment.
"Adding Chris is another move in our continuing effort to build a deep and flexible pitching staff," said Dipoto. "His composure and solid feel to pitch has produced positive results at all levels throughout his career."
Heston, 28, made the Opening Day roster for the second straight season and made four relief appearances with San Francisco last season (6 ER, 5.0 IP) before spending most of the year with AAA Sacramento where he was 2-9 with a 4.54 ERA (41 ER, 81.1 IP) with 53 strikeouts in 15 games, including 14 starts. He was placed on the 60-day disabled list with an oblique strain on June 29 and was sent on a minor league rehabilitation assignment on Aug. 13 with the AZL Giants (2 GS), High-A San Jose (1 GS) and AAA Fresno (2 GS). He was recalled from his rehab assignment on Sept. 6 (not activated) and was removed from the 60-day DL on Nov. 6.
In parts of three Major League seasons with the Giants, he is 13-12 with a 4.16 ERA (87 ER, 188.0 IP) with 148 strikeouts in 38 games, including 32 starts. In 2015, he was 12-11 with a 3.95 ERA (78 ER, 177.2 IP) with 141 strikeouts in 31 starts with San Francisco, including tossing a no-hitter on June 9, 2015 against the New York Mets. In seven minor league seasons with San Francisco, he is 48-54 with a 3.64 ERA (347 ER, 857.1 IP) with 707 strikeouts in 151 games, including 145 starts. He was drafted by the Giants in the 12^th round of the 2009 MLB First-Year Player draft out of East Carolina University (Greenville, NC).
Shaffer, 25, was acquired from Tampa Bay in a 5-player trade on Nov. 18. He appeared in 20 games over three stints with Tampa Bay in 2016 (8/3-10, 8/20-24 & 9/6-end of season). Overall he hit .250 (12x48) with 5 runs scored, 6 doubles, 1 home run, 4 RBI and 5 walks, while appearing in games at first base, third base and designated hitter. The 6-foot-3, right-handed batter spent the majority of the season with AAA Durham in the International League, batting .227 (97x428) with 49 runs scored, 27 doubles, 11 home runs, 48 RBI, 65 walks and 4 stolen bases in 119 games. Shaffer was recently rated by Baseball America as the Best Infield Arm in the Rays organization following the 2016.  
Shaffer was selected by Tampa in the first round (25th overall) in the 2012 MLB First-Year Player Draft out of Clemson University. He was originally selected by the Los Angeles Dodgers in the 25th round in the 2009 draft out of Providence (Charlotte, NC) High School, but did not sign. He made his Major League debut with the Rays in 2015 and appeared in 31 games at 4 different positions (1B, 3B, RF, DH) during his rookie campaign. Shaffer recorded his first career hit, a solo home run, in his second career start on August 4, 2015 at Chicago-AL off Daniel Webb. Over 5 seasons in the minor leagues with the Rays, Shaffer hit .246 (452x1834) with 251 runs scored, 120 doubles, 8 triples, 71 home runs, 283 RBI, 226 walks and 18 stolen bases in 501 games. He was named the Rays Minor League Player of the Year following the 2015 season after leading all Rays minor leaguers with 26 home runs and tying for 2nd with 72 RBI between AA Montgomery and AAA Durham. He also started at third base and hit cleanup for the U.S. team in the 2015 All-Star Futures Game at Great American Ballpark in Cincinnati.