Royals complete minor trade with Giants

The Kansas City Royals announced that they have acquired right-hander Mason Black from the San Francisco Giants. Minor league righty Logan Martin heads in the other direction. The Giants designated Black for assignment last week. The Royals’ 40-man roster count climbs from 36 to 37.

Black, who will be 26 next month, joins a new organization for the first time in his career. The Giants took him with a third-round pick in 2021. As he climbed the minor league ladder, he was generally regarded as one of the club’s top ten prospects.

He hasn’t yet delivered much at the big league level. Between 2024 and 2025, he tossed 40 1/3 innings for the Giants, allowing 6.47 earned runs per nine. His 8% walk rate in that time was around average, but his 19.1% strikeout rate was subpar.

His work in the minors has been better, but he’s coming off a poor season. From 2022 to 2024, he logged 320 minor league frames with a 3.77 ERA, 28.2% strikeout rate and 9.5% walk rate. In 2025, he pitched 119 1/3 Triple-A innings, posting a 5.81 ERA in the hitter-friendly Pacific Coast League. He struck out 21.5% of opponents and walked them at an 11.7% pace. That got him bumped off San Francisco’s roster, but Kansas City will take a shot on him.

Black still has one option season remaining, so the Royals don’t need to keep him on the big league roster. He could be kept in Triple-A Omaha as rotation depth. It’s also possible they experiment with him in a relief role. Black has mostly been a starter in his career, but his final five appearances in 2025 were out of the bullpen for Triple-A Sacramento. In those, he faced 25 batters, striking out six while giving out two walks.

To get Black aboard, the Royals are parting with Martin. He was their 12th-round pick in 2023. Last year, he tossed 102 innings at the Single-A level with a 3.62 ERA, 22.9% strikeout rate and 7.5% walk rate. This year, he moved up to High-A and logged 91 1/3 innings with a 3.45 ERA, 20.6% strikeout rate and 9.5% walk rate. He has been pitching in the Arizona Fall League of late, though with 12 earned runs allowed in 11 innings. Back in May, Eric Longenhagen and James Fegan of FanGraphs gave Martin an honorable mention on their list of the top prospects in the Royals system.

Martin is a bit of a lottery ticket since he hasn’t yet reached Double-A, but the Giants are surely happy to get any kind of chance at a return for a player they designated for assignment. Martin will be Rule 5 eligible a year from now, so the Giants can use that time to decide if he’s worth a roster spot. The Royals, meanwhile, weren’t going to get anything from Martin in the near term, whereas Black has a chance to contribute to the big league club in 2026. The Royals presumably also hope that Black has the greater upside as a former third-round pick and notable prospect.