Giants Trade Reiver Sanmartin To Nationals

12:45pm: The two teams have announced the swap.

12:30pm: The Nationals are acquiring left-handed reliever Reiver Sanmartin from the Giants, reports Spencer Nusbaum of The Athletic. Minor league righty Robert Cranz is headed back to San Francisco in return. The Giants designated Sanmartin for assignment earlier in the week.

Sanmartin, 30, pitched 21 1/3 innings with the Giants this past season and logged a 4.22 ERA, 17.2% strikeout rate, 7.5% walk rate and colossal 63.8% ground-ball rate. The 6’1″ southpaw has pitched in parts of five major league seasons — the other four all coming with Cincinnati — and carries a 5.37 ERA in 105 2/3 frames overall.

Sanmartin works primarily off a sinker that sat 91.7 mph this past season. He complements the pitch with a slider and changeup both used about equally (roughly 27% apiece) and a seldom-used four-seamer that checks in about a half-mile north of Sanmartin’s sinker.

In parts of 10 minor league seasons, Sanmartin carries a 3.40 ERA in 564 1/3 innings. That includes a 4.04 mark in 214 Triple-A frames, where he’s fanned a batter per inning (23.6% overall) with very strong command (6.2% walk rate). As one might expect looking at his big league work, Sanmartin has a track record of posting huge ground-ball rates throughout all levels of the minors — including a rate north of 60% across the past three Triple-A campaigns.

Since Sanmartin is out of minor league options, he’ll need to break camp with the Nationals next year or else be designated for assignment. Given that the Nats traded a relatively decent relief prospect for him, it seems likely that president of baseball operations Paul Toboni envisions Sanmartin opening next year in at least a middle relief capacity.

Sanmartin crossed two years of major league service time during the 2026 season, so the Nats can control him for another four seasons. The bullpen-hungry Giants would probably have preferred to hang onto him themselves, but San Francisco finished the season with an astounding 16 players on the 60-day injured list and needed to open 40-man roster spots for most of them no later than this past Monday afternoon, leading to some tough decisions.

As for the 23-year-old Cranz, he was Washington’s seventh-round pick (No. 200 overall) in the 2024 draft. The Oklahoma State product posted strong numbers at every minor league stop until getting tagged for 17 earned runs in 11 2/3 frames during his first promotion to Triple-A late in 2026. It was a rude introduction to the game’s top minor league level, but Cranz had posted a 2.02 ERA across two Class-A levels in 2025, a 2.25 mark in 16 High-A frames this season and a 3.42 mark in 26 1/3 Double-A innings.

Along the way, Cranz has shown an aptitude for missing bats but has also demonstrated poor command. He’s fanned more than 32% of his opponents in pro ball but has also issued walks at an untenable 12.6% clip. More advanced Triple-A hitters, in particular, exploited his lack of precision; they drew walks at a mammoth 20% clip against just a 13.8% strikeout rate.

While Cranz’s Triple-A debut was ugly to say the least, it’s a relatively small number of innings for a young pitcher who’d already pitched more innings by the time he was promoted (42 1/3) than he did in all of 2025 (35 1/3). Cranz comes to the Giants with a repertoire that features a four-seamer just north of 95 mph, an 88 mph cutter, an 83 mph slider and a very seldom-used changeup that also checks into the 83-84 mph range. He wasn’t considered a top prospect in Washington’s system but is pretty close to MLB readiness and could factor into San Francisco’s bullpen as soon as the 2027 season if he can make some strides with his command.