The Mariners acquired left-handed reliever Caleb Ferguson from the Pirates for minor league right-hander Jeter Martinez. Righty Collin Snider has been designated for assignment as the corresponding move. Ferguson is playing on a one-year, $3MM contract and is a free agent at season’s end.
Ferguson, 29, is in the midst of a strong season with Pittsburgh. He’s pitched 43 1/3 innings and logged a 3.74 ERA with a 19.3% strikeout rate and 8% walk rate. He’s allowed only one homer on the season and kept just under 50% of his opponents’ batted balls on the ground.
While Ferguson isn’t a flamethrower who misses bats in bunches — he’s averaging 94.1 mph on his four-seamer this season — he avoids hard contact better than any other reliever in the game. Ferguson’s 83.5 mph average exit velocity is the lowest of any pitcher in Major League Baseball (min. 40 innings). His 25.2% hard-hit rate is second, trailing only Padres standout lefty Adrian Morejon.
Ferguson has pitched in parts of seven major league seasons. He’s totaled a 3.69 earned run average in 305 big league innings. The southpaw typically misses more bats than he has in 2025 (career 26.4% strikeout rate), but he’s currently sporting his lowest walk rate since the shortened 2020 season and has never limited hard contact as well as he’s managed to this year. Ferguson has been an absolute monster against left-handed opponents, limiting them to a pitiful .167/.257/.182 slash in 74 plate appearances. He’s also been strong against right-handers, however, holding them to a .250/.327/.354 slash. It’s not quite dominant, but this is his best production versus righties since 2022.
The Mariners have only had one reliable left-hander in their bullpen this season: Gabe Speier. They’ve given brief looks to Tayler Saucedo, Blas Castaño and Jhonathan Diaz, but no one from that group has even pitched five innings out of the big league bullpen. Ferguson gives skipper Dan Wilson a second southpaw option who, like Speier, can handle both lefties and righties.
Seattle is known to be on the lookout for high-impact talent at the back of the bullpen. Ferguson isn’t necessarily that marquee arm they’ve been seeking, but in all likelihood he’ll be just one of multiple relievers acquired. The Mariners are reportedly making a run at Twins closer Jhoan Duran and have also been tied to young, controllable bullpen arms in Colorado like Seth Halvorsen and Juan Mejia.
As for the Pirates, they’ll spin their low-cost investment in Ferguson into the 19-year-old Martinez. The 6’4″ righty, signed out of Mexico for a $600K bonus during the 2022-23 signing period, has started 16 games against older and more advanced competition with the Mariners’ Low-A affiliate. He’s struggled to a 6.18 ERA due in no small part to a 13.2% walk rate.
Martinez posted strong ERAs in prior seasons with the Mariners’ affiliate in the Dominican Summer League, however, and he’s shown plenty of ability to miss bats with a mid-90s fastball that can scrape triple digits. Baseball America ranked Martinez 22nd among Seattle prospects earlier this month. FanGraphs ranked him 15th in the system last month, where Eric Longenhagen praised that heater and a pair of secondary pitches (slider, changeup) that could be plus pitches. Command is the biggest issue, but Martinez is still more than two years away from needing to be added to the 40-man roster, so the Pirates will have awhile to try to rein in the free passes and keep him in the rotation. If a move to the bullpen ends up being necessary, it’s easy enough to imagine Martinez’s already impressive fastball playing up a bit further.
Ken Rosenthal of The Athletic reported the Mariners were acquiring Ferguson. Adam Jude of The Seattle Times reported that Martinez was going the other way.