Castillo didn't factor into the decision in Friday's 3-2 loss to the Blue Jays, giving up two runs on six hits and two walks over five innings. He struck out four.

EDGE Analysis

For the second straight start, Castillo didn't pitch into the sixth inning, and this time he came away with a season low in strikeouts, managing only 18 called or swinging strikes in 95 pitches -- a far cry from his 28.9 percent CSW rate on the year. The right-hander also served up his first homer of 2023, a second-inning solo shot by Alejandro Kirk. Despite what was for him a relatively mediocre outing, Castillo still sports a 1.82 ERA, 0.92 WHIP and 38:8 K:BB through 34.2 innings, and he'll look to regain some dominance in his next start, likely to come in Oakland next week.

Castillo didn't factor in the decision against St. Louis on Saturday, allowing three runs on seven hits and two walks while striking out eight batters over five innings.

EDGE Analysis

Castillo labored in the outing, needing 100 pitches to get through five frames and surrendering season highs with seven hits and three runs. Still, he racked up an impressive 19 swinging strikes and punched out eight batters. All of the damage against the hurler came in the first and third innings, and Castillo finished his outing by retiring the final five batters he faced -- three by strikeout. The right-hander is tentatively projected to take on the Blue Jays in Toronto his next time out.

Castillo (2-0) allowed two hits over seven scoreless frames Sunday, striking out nine and earning a win over Colorado.

EDGE Analysis

Castillo completely dominated the Rockies on Sunday. He carried a perfect game into the seventh inning before giving up a pair of singles. His nine punchouts and 19 whiffs were both his best marks of the season. Castillo is now sporting a stellar 0.73 ERA and 26:4 K:BB through four outings. He's projected to face the Cardinals at home next week.

Castillo did not factor in the decision against the Cubs on Monday, pitching six innings and allowing two runs on six hits and two walks while striking out five batters.

EDGE Analysis

Castillo wasn't quite as dominant as in his first two starts of the campaign, when he threw a combined 11.2 scoreless frames during which he allowed just three hits. Though he gave up his first two runs of the season Monday, the talented right-hander earned a quality start and kept the Mariners competitive in a low-scoring affair. Castillo has posted a minuscule 1.02 ERA through his first three starts, though has just one win to show for it.

Castillo moved to 1-0 after striking out six over 5.2 scoreless innings in Tuesday's 11-2 victory over the Angels. He scattered two hits and two walks in the 99-pitch outing.

EDGE Analysis

Doubles off the bats of Taylor Ward and Brandon Drury were about the only damage on the night for Castillo, who blanked the Angels midway through the fifth inning before departing with an 8-0 lead. He's yet to allow a run through his first two starts and sports a microscopic 0.43 WHIP over 11.2 innings.

Castillo did not factor into the decision Thursday versus the Guardians, yielding just one hit and no walks over six shutout frames in a 3-0 victory. He struck out six.

EDGE Analysis

The only baserunner Castillo allowed on the night was a leadoff single by Will Brennan in the third inning which actually glanced off the pitcher's head and knocked his cap off, although the right-hander was fine. The incident clearly didn't spook Castillo, as he fanned the next three to get out of the frame and start a streak of 12 straight batters retired to finish off his night. He needed only 76 pitches to cruise through his six innings, collecting 13 swinging strikes and a 37 percent CSW rate along the way. The four-seamer was Castillo's most-used pitch in this one, just as it was after he came over to Seattle in a trade last August.

Castillo has been named the Mariners' Opening Day starter, Ryan Divish of The Seattle Times reports.

EDGE Analysis

Robbie Ray was another good candidate, but Castillo gets the nod. The right-hander will take the ball March 30 at home against the Guardians and Shane Bieber.

Castillo has allowed three runs (two earned) on six hits, two walks and a hit batsman while recording six strikeouts across 4.1 innings during his first two Cactus League starts.

EDGE Analysis

Castillo, who opted to forgo pitching for the Dominican Republic in the World Baseball Classic to instead go through his first full spring training with the Mariners, is getting a decent amount of work in thus far. The right-hander only worked up to 22 pitches in his most recent start Monday against the Cubs, however, so he's likely to see a notable bump in workload in his next start.

Mariners president of baseball operations Jerry Dipoto told reporters Wednesday that Castillo won't pitch in the World Baseball Classic for the Dominican Republic, Daniel Kramer of MLB.com reports.

EDGE Analysis

"It's a choice that we made together," Dipoto told reporters. The Mariners want Castillo to have a full spring training in his first full season with the club, and Castillo agreed. The right-hander was excellent in his time with Seattle after being traded from the Reds shortly before last season's deadline, producing a 3.17 ERA, 77:17 K:BB and 1.10 WHIP over 65.1 innings across 11 starts. He'll open the year as the ace of Seattle's pitching staff, with the combination of last season's body of work and that of his previous campaigns suggesting he'll be a top-end fantasy asset again in 2023.

Castillo will start Game 1 of the AL Wild Card Series against the Blue Jays on Friday, Ryan Divish of The Seattle Times reports.

EDGE Analysis

Castillo finished the regular season Saturday by giving up one run over six innings against the A's, and he'll take the mound in the postseason opener for Seattle. The 29-year-old righty was acquired from the Reds at the trade deadline and delivered a 3.17 ERA, 1.10 WHIP and 77:17 K:BB across 65.1 frames in 11 starts with the Mariners.