Chris Heston to Mariners: Latest Trade Details, Comments, Reaction

The Seattle Mariners reportedly added some pitching depth Wednesday.

According to Jon Morosi of MLB Network, the San Francisco Giants traded right-handed pitcher Chris Heston to Seattle. Chris Cotillo of SB Nation confirmed the trade through a source but added the return package was unknown.

Alex Pavlovic of CSN Bay Area noted the Giants were looking to clear space on their 40-man roster for recently signed closer Mark Melancon. Pavlovic added that "at least a couple of teams had reached out" to San Francisco to see if Heston was available, with the free-agency market lacking impact starters.

The future looked bright for the 28-year-old in 2015, when Heston made 31 starts for the Giants, posting a 3.95 ERA, a 1.31 WHIP and 141 strikeouts in 177.2 innings. He threw a no-hitter while striking out 11 batters against the eventual National League champion New York Mets on June 9 of that year, and it was easy to envision his becoming an anchor in San Francisco's rotation.

However, the Giants added Johnny Cueto, Jeff Samardzija and Matt Moore, and Heston started the 2016 campaign in the bullpen. He made four appearances in April, struggling with a 10.80 ERA and just three strikeouts in five innings before being sent to the minors.

According to Charlie Wilmoth of MLB Trade Rumors, Heston dealt with an oblique injury in the minors, which partially explained his 4.54 ERA in 81.1 innings.

The Giants rotation is largely set, with Madison Bumgarner, Cueto, Moore, Samardzija, Ty Blach and Matt Cain as potential options, so Heston will have a better opportunity in Seattle.

Although the Mariners finished an impressive ninth in the majors in starting pitcher ERA in 2016, Jon Heyman of FanRag Sports suggested they needed to add another starter in the offseason. Bob Dutton of the News Tribune noted the decision to trade Taijuan Walker to the Arizona Diamondbacks in November created that need.

The Mariners were 86-76 but missed the playoffs in 2016. If Heston can return to the form he demonstrated in 2015 as a formidable piece behind Felix Hernandez, they can challenge the reigning American League West champion Texas Rangers on the back of their starting staff.