2025 Transactions: Nationals Sign Foster Griffin, Refsnyder to Mariners

Another NPB standout is coming back to North America, as left-hander Foster Griffin is joining the Nationals for the 2026 season. That move was one of several to get done on December 22, a day that also saw the Mariners bring in former Red Sox Rob Refsnyder.

Mariners sign Refsnyder

The Mariners announced that the team signed outfielder Rob Refsnyder to a one-year deal.

Refsnyder was, largely, a productive hitter with the Red Sox after joining the team in 2022. The 34-year-old slashed .307/.384/.497 in 2022, and continued to produce. Refsnyder hit 20 combined home runs over 163 games between 2024 and 2025.

While Refsnyder saw significant plate appearances against both lefties and righties in 2024, he was primarily a platoon bat against lefties this past year. Refsnyder has generally hit lefties very well; the right-hander hitter slashed .302/.399/.560 with seven home runs and 16 extra-base hits over 138 PA against left-handed pitching.

Griffin back in North America

The Nationals announced that the team signed left-hander Foster Griffin to a Major League deal. It’s a one-year deal that is reportedly worth $5.5MM.

Griffin was a first-round pick a decade ago by the Royals but barely pitched in the Majors before going to Japan. The left-hander worked in eight games between 2020 and 2022 at the MLB level, split between the Royals and Blue Jays.

The 30-year-old joined the Yomiuri Giants of the NPB and pitched well overall across his three seasons in Japan. He didn’t have a BB/9 north of 2.2 in those three seasons. Griffin’s best year was in 2024, a season that saw him strike out 149 over 138 and post a 2.93 ERA.

Griffin wasn’t a hard thrower in Japan, as his fastball averaged about 90 MPH with the Giants. (h/t NPB Pitch Profiler). He did, however, induce a lot of swing-and-miss action on his low-80s changeup. He also added some weapons, including a slider, splitter, and two-seamer.

Phillies grab Pop

The Phillies signed reliever Zach Pop on December 22.

Pop, who bounced around the Cubs, Mets, and Mariners’ organizations in 2025, struck out 23 over 19.1 IP in the Minors this past season. However, he was hit hard at the MLB level, as he surrendered four home runs and 11 earned runs over 6.2 IP.

The 29-year-old works with a hard sinker that topped out at 99 MPH in Triple-A this season, plus a slider and cutter.

Other moves

The Athletics designated left-hander Ken Waldichuk for assignment. It was a corresponding move to add Jeff McNeil to the 40-man roster. McNeil was acquired via trade from the Mets on December 22.

Cleveland signed reliever Codi Heuer to a Minor League deal. It came with a non-roster invite to Spring Training.