The Royals announced that they have acquired right-hander Mason Black from the 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, 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 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 but with 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 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.

More to come.