Mariners Acquire Trent Thornton From Blue Jays

2:05pm: The Mariners have now announced the trade, with Gonzales indeed transferred to the 60-day IL as the corresponding move. The lefty has been on the IL since late May due to a left forearm strain and has yet to begin a rehab assignment. He’ll be eligible to return from the IL as soon as this weekend but that doesn’t seem to be a possibility.

2:00pm: The Mariners are acquiring right-hander Trent Thornton from the Blue Jays, reports Jeff Passan of ESPN. Thornton was designated for assignment last week when the Jays acquired Génesis Cabrera. The Mariners are sending infielder Mason McCoy to the Jays in exchange. The M’s will need to open a 40-man roster spot for Thornton, though they can do that fairly easily by transferring Marco Gonzales to the 60-day injured list.

Thornton, now 29, came over to the Blue Jays in a November 2018 trade that sent utility player Aledmys Díaz to the Astros. The righty jumped into Toronto’s rotation the next year and tossed 154 1/3 innings with a 4.84 earned run average. He struck out 22% of batters faced while walking 9% of them.

But in 2020, he was limited to just three starts by elbow inflammation and has been transitioned into a relief role since then. He served as a frequently-optioned depth piece for the Jays in the past few seasons, logging 100 1/3 frames in the big leagues since the start of 2021 with a 4.31 ERA, 22% strikeout rate and 8% walk rate. He’s also been able to throw 66 1/3 innings at the Triple-A level with a 2.98 ERA, striking out 21.8% of opponents while walking 10.9%.

Despite those decent numbers, Thornton was pushed down Toronto’s depth chart by other acquisitions and has only been able to make four big league appearances this year. He’s also in his final option year, meaning he’ll be out of options next year and will therefore have diminished roster flexibility. But the Mariners will still have the ability to option him for the rest of the year, allowing him to provide them with a bit of extra depth for their pitching staff. Daniel Kramer of MLB.com relays that Thornton will initially report to Triple-A Tacoma.

Heading the other way is McCoy, 28, who was originally drafted by the Orioles but was traded to the Mariners in a cash deal in April of 2022. Baseball America ranked him the 29th best prospect in Baltimore’s system in 2020, praising his glove and bat-to-ball skills but expressing some concern about a lack of future power.

Since that trade, he’s been playing for Triple-A Tacoma in the hitter-friendly Pacific Coast League. He hit 20 home runs last year but struck out in 25.8% of his plate appearances. His .256/.332/.473 batting line amounted to a wRC+ of 96 in that offensively-charged environment. This year, he’s added another 11 homers but struck out at a 29.5% clip. His .234/.330/.407 line this year translates to a 77 wRC+.

Despite the subpar offense, he should have a decent floor due to his other qualities. He stole 22 bases last year and has swiped another 20 already here in 2023. He also has defensive versatility, having played the three infield positions to the left of first base as well as some brief appearances in the outfield. He will be eligible for minor league free agency at the end of this season if not added to Toronto’s 40-man roster.