Heston was designated for assignment Wednesday, Ryan Divish of The Seattle Times reports.

EDGE Analysis

The Mariners landed outfielder Andrew Alpin from the Astros on Wednesday, so in order to place him on the 40-man roster, someone needed to get the boot. Heston was ultimately the odd-man out after struggling significantly in the big leagues, so he'll work on regaining his confidence in a starting role with Triple-A Tacoma as an organizational depth piece.

Heston was optioned to Triple-A Tacoma on Monday.

EDGE Analysis

Heston was sent back to Tacoma after getting roughed up during his spot start against the White Sox on Sunday, allowing seven runs through three innings while walking four batters and only striking out two. Given he has made two appearances for the big club this season and conceded 12 runs across just five innings, the Mariners may decide to look elsewhere should they need another spot starter. Emilio Pagan was recalled from Triple-A to take his spot on the roster for the time being.

Heston (0-1), just recalled from Triple-A Tacoma, gave up seven earned runs on seven hits and four walks over three-plus innings in Sunday's 8-1 win over the White Sox. He struck out two.

EDGE Analysis

Heston was nowhere close to effective in his spot start, getting only 39 of his 72 pitches into the strike zone and providing no relief for a short-handed and fatigued Mariners bullpen. The right-hander gave up five runs in the first in a quartet of singles and a solo home run. The 29-year-old has now given up 12 earned runs in the five innings spanning his two appearances for the Mariners this season, leading to a 21.60 ERA and 3.80 WHIP. With the Seattle rotation still down multiple starters, Heston could well take the mound again at Fenway Park versus the Red Sox next Friday.

Heston was recalled from Triple-A Tacoma and will draw the start for Sunday's game against the White Sox, Shannon Drayer of 710 ESPN Seattle reports.

EDGE Analysis

With the Mariners' starting rotation in absolute ruins due to numerous injuries, Heston will be called upon to take the mound Sunday against the White Sox. The righty has made six starts with Triple-A Tacoma this season, posting a 3.41 ERA and 1.17 WHIP over 31.2 innings. The White Sox have struggled against right-handed pitching this season, posting a collective .679 OPS against righties, which is good for fourth-worst in the majors.

Heston (2-0) fired a scoreless 5.2 innings in the Rainiers' 2-0 win over Sacramento on Monday, giving two hits and two walks. He struck out five.

EDGE Analysis

It was a marked departure from Heston's only appearance with the big-league club this season, an April 25 outing in which he yielded five earned runs on seven hits and a walk over two innings against the Tigers. The 29-year-old right-hander figures to continue providing Tacoma's rotation with an experienced presence for the time being, although any injuries to the Mariners' rotation could eventually prompt another move up later this season.

Heston was optioned to Triple-A Tacoma on Wednesday, Greg Johns of MLB.com reports.

EDGE Analysis

Called upon in relief of Felix Hernandez (shoulder) on Monday, Heston gave up five runs on seven hits (including two home runs) and a walk in two innings of work. He will head down for now with the team needing to add fresh arms to its bullpen. Heston has posted a 3.18 ERA and 1.23 WHIP in 17 innings with Tacoma so far this season.

Heston gave up five runs on seven hits and a walk in just two innings of relief against Detroit on Tuesday.

EDGE Analysis

He took a bad situation (Felix Hernandez struggling and then being removed early) and made it worse, helping the Tigers on their way to a 19-run evening. Heston was only just called up this weekend as a long-relief arm, and this outing could very well get him sent right back down.

Heston was recalled from Triple-A Tacoma on Sunday, NBC Sports Bay Area's Alex Pavlovic reports.

EDGE Analysis

Heston was in competition for the No. 5 spot in the Mariners' rotation during spring training, but was ultimately sent to the minors near the end of camp. The 29-year-old has posted a 3.18 ERA over 17 innings in the Tacoma rotation, but will join the Mariners as a bullpen arm.

Heston was optioned to Triple-A Tacoma on Sunday, Ryan Divish of the Seattle Times reports.

EDGE Analysis

Heston spent the majority of his 2016 campaign with the Giants' Triple-A affiliate and is slated to being the 2017 season in Triple-A again. If an injury occurs to one of the team's major league starters, Heston would be a prime candidate to receive an in-season call-up.

Heston gave up six earned runs on seven hits and one walk over 2.1 innings in Tuesday's 8-5 Cactus League loss to the A's.

EDGE Analysis

Heston surrendered five doubles among his seven hits and came unraveled in the third, when the A's touched him up for six runs overall. The right-hander is expected to start the season at Triple-A Tacoma and figures to be a prime candidate for a call-up at some point in the regular season when the Mariners are down a man in their rotation.