Twins are about to get best of Mariners' pitching staff

The Minnesota Twins are riding a 12-game winning streak into Sunday's series finale with the Boston Red Sox, but to keep their success going, they'll likely have to contend with the heart of the Seattle Mariners' pitching staff next week.

The Mariners visit Target Field for a four-game series beginning on Monday night with Luis Castillo, Emerson Hancock, George Kirby and Logan Gilbert scheduled as probable starters.

Seattle's starting rotation comes into this week's series with the fourth-lowest average allowed (.211), third-lowest earned-run average (3.02) and lowest WHIP (1.02) in the majors entering Sunday's action, and each matchup has a difficult task for the Twins.

Castillo is a three-time All-Star and has enjoyed a strong start to the season with a 3-4 record and 3.46 ERA. Castillo is also posting a 4.7% walk rate (88th percentile among starters) and a 28.7% strikeout rate (80th percentile) this season, but his 32.7% chase rate (82nd percentile) will be the biggest challenge for the Twins.

Woods Richardson will oppose Castillo and has been solid for the Twins since stepping into the fifth spot in the rotation. Woods Richardson allowed one run on two hits with a walk and five strikeouts in his first start of the season April 13 against the Detroit Tigers but has allowed three runs on 14 hits and three walks with eight strikeouts over 8 2/3 innings pitched in his last two starts.

A top prospect in the Mariners organization since he was selected with the sixth overall pick in the 2020 MLB draft, Hancock has cracked Seattle's rotation going 3-3 with a 4.75 ERA. 

This could be a spot where the Twins can take advantage of as Hancock has had trouble limiting hard contact. Hancock has allowed a 47.9% hard hit rate (ninth percentile) this season, although his average exit velocity has dropped from 89.2 mph to 87.8 mph this season.

Hancock will face Ober, who has recovered from a rough first start to become one of the Twins' top starters. Ober has gone 2-0 with a 1.48 ERA over his last four starts and is holding opposing hitters to a .136/.193/.222 line during that timeframe.

Kirby has developed into one of the game's top starters after making his first All-Star appearance last season. After going 13-10 with a 3.35 ERA last year, Kirby has a 3-2 record with a 3.76 ERA this year.

Kirby doesn't walk batters with a 2.6% walk rate (98th percentile), but he also doesn't allow hard contact with a 30% (87th percentile) hard-hit rate and 87.5 mph exit velocity (71st percentile).

The Twins will counter with Paddack, who is coming off his best start of the year after allowing two hits and a walk with six strikeouts over six shutout innings in Friday's 5-2 win over the Red Sox.

Thursday's matchup could be the best of the series when Gilbert takes on López. Gilbert is 3-0 with a 1.69 ERA this season, and his metrics back it up with a the highest pitching run value in the majors this season at +13.

Gilbert's improvement has come with the addition of a cutter which hitters are hitting .167 against this season, and the right-hander typically doesn't walk batters with a 4.7% walk rate last season.

Gilbert's 7.3% walk rate this year is a career high, however, and it could open the door for López. López had some concerns after his velocity dropped in starts against the the Chicago White Sox and Los Angeles Angels, but he rebounded to allow one run on five hits and a walk with eight strikeouts in Saturday's 3-1 win over the Red Sox.

If both pitchers are on their game, it could be an entertaining finale to the series.