The Mariners won’t leave empty-handed from the Winter Meetings after acquiring right-hander Chris Heston on Wednesday night from San Francisco for a player to be named later.
"Adding Chris is another move in our continuing effort to build a deep and flexible pitching staff," general manager Jerry Dipoto said. "His composure and solid feel to pitch has produced positive results at all levels throughout his career."
Heston, 28, missed much of last season because of a severe oblique injury after going 12-11 with a 3.95 ERA in 31 starts for the Giants in 2015. He is not yet eligible for arbitration, which makes him a low-cost acquisition.
The Mariners cleared space for Heston on their 40-man roster by designating infielder/outfielder Richie Shaffer for assignment. The trade could be completed as soon as the Rule 5 Draft concludes on Thursday.
While the trade bolsters the Mariners’ depth, Dipoto said the club is continuing to seek a veteran pitcher for their rotation.
Heston opened last season in the Giants’ bullpen but was sent to Triple-A Sacramento in late April after allowing six runs and nine hits over five innings in four appearances.
After going 2-8 with a 3.77 ERA in 13 games, including 12 starts, Heston was diagnosed with a strained oblique and placed on the 60-day disabled list.
The Mariners acquired Shaffer, 25, from Tampa Bay in a five-player deal on Nov. 18. He batted .250 last season with one homer and four RBIs for the Rays in 20 games over three tours.
Shaffer spent most of the season at Triple-A Durham, where he batted .227 with 11 homers and 48 RBIs in 119 games.
Bob Dutton: @TNT_Mariners