Mason Black

SP/RP · R/R · age 26.8 · KC

OCTOBER OK

Roster status
OPTIONED
Service thru 2025
0+051
Service now / projected
0+110 / 0+110
Option years left (2026)
1 (using one in 2026)
Assignments left this season
2 of 5
Contract (2027)
PRE-ARBITRATION / AUTO-RENEWAL
Acquired
Trade (SFG) Nov'25
Outrighted / DFA'd before
0 / 1
Contract
none listed

Next 90 days, by the model

Stays put
36%
Designated
48%
Optioned
11%
Traded
1%
Released or non-tendered
3%

Pushing the cut risk up: this season's WAR (-0.51) raises it, roster status (3) raises it, prior DFAs (1) raises it.

Context the model does not weigh: ZiPS projects 0.8 WAR, -0.5 WAR this season; 8 OF on the 40-man, of whom Joshua Rojas is headed to free agency.

Trained on every 40-man roster snapshot since 2011 and what happened in the following 90 days; it sees roster status, options, service, history and last season's line, not this season's performance or the club's intentions. How well it does.

Is there a job for him next year?

KC returns 8 IF on the 40-man once 2 free agents leave; about 8 IF jobs survive a normal winter. By his own recent record he ranks 8th among the returners (-1.0 WAR against a bar of -1.0), which the calibrated model turns into 57% kept through the tender deadline. Ranked by ZiPS and Steamer instead, which credit his longer track record, he is 8th (0.5 WAR, bar 0.5), worth 73% kept on the same model.

By recent record: returning IFProj. WAR
1. Bobby Witt Jr.6.5
2. Maikel Garcia3.2
3. Tyler Tolbert1.8
4. Michael Massey1.8
5. Vinnie Pasquantino1.0
6. Nick Loftin0.9
7. Salvador Perez0.2
8. Mason Blacklast job-1.0
By ZiPS / Steamer: returning IFProj. WAR
1. Bobby Witt Jr.6.5
2. Maikel Garcia3.5
3. Vinnie Pasquantino1.9
4. Salvador Perez1.9
5. Michael Massey0.8
6. Nick Loftin0.7
7. Tyler Tolbert0.7
8. Mason Blacklast job0.5

Departing free agents are excluded; players on club, mutual or player options are counted as returning. The kept probability is calibrated on every September since 2012 using the recent-record projection; the ZiPS/Steamer reading uses the same model with a different ranking, so treat it as a second opinion rather than a calibrated number. Salary enters once arbitration projections publish in October.

October: Post-season eligible

On the 40-man before noon ET Sep 1. He stays eligible as long as he remains on the 40-man or 60-day IL through the post-season; an outright after the cutoff would end automatic eligibility.

The post-season eligibility list is fixed at noon ET on September 1: everyone on the 40-man, the 60-day IL or the military list at that moment, who then stays there without interruption. Attachment 25 (Major League Rule 40)

What happens if the club…

option him to the minors
Yes, 1 option year left. 2 of the five optional assignments for 2026 remain. A 2026 option year is already used (115 days), so further trips this season cost nothing extra. Once down he must stay 10 days unless he replaces an injured or traded player.
Option years and the 20-day rule · Five optional assignments per season · Minimum stay on option
designate him for assignment (or put him on outright waivers)
The club has 7 days to trade him, pass him through outright waivers, or release him; he is paid at the major-league rate and keeps accruing service in the meantime. On outright waivers any club can claim him for $50,000, worst record first, and the claiming club takes his contract. If he clears, the club can outright him to the minors and he has no say; he stays under club control on a minor-league deal. He would then be Rule 5-eligible and would hold XX-D rights against any future outright. Post-season: an outright after the September 1 cutoff ends his automatic eligibility. He could only return as an approved injury replacement, and only if he accepts the outright and stays on a minor-league reserve list in the organization without interruption; a release makes him ineligible for anyone this October.
Designated for assignment: 7 days · Outright waivers · Article XX-D: the right to walk
release him
Release waivers cost a claiming club $1 but the claimant assumes the whole contract, so expensive players clear. The club owes the full unpaid balance of this season's salary, offset by whatever another club pays him this year. A released player is not post-season eligible for any club this year.
Release waivers and termination pay · Which rate a split contract pays at release
trade himBLOCKED
Not now: players on major-league contracts cannot be traded after the Aug 3 deadline until the day after the World Series.
Trade deadline · 10-and-5 rights · June 15 no-trade for free-agent signees
renew him for next year
Pre-arbitration: the club sets his 2027 salary near the minimum ($780,000 floor) and he has no leverage beyond a non-tender.
Minimum salaries · Tender deadline

What the rules say about him

Option years, season by season

SeasonDays on optionOption year usedStints
2026115yesMar 17, 2026 to Apr 19, 2026 (25d, spring training)May 5, 2026 to May 27, 2026 (22d)Jun 19, 2026 to Aug 7, 2026 (49d)Aug 27, 2026 to now (19d)
2025192yesMar 5, 2025 to Jul 2, 2025 (106d, spring training)Jul 5, 2025 to Sep 29, 2025 (86d)
2024106yesMay 13, 2024 to May 17, 2024 (4d)May 24, 2024 to Jun 25, 2024 (32d)Jun 26, 2024 to Aug 31, 2024 (66d)Sep 27, 2024 to Oct 1, 2024 (4d)

Transaction log

Aug 27, 2026OptionedKansas City Royals optioned RHP Mason Black to Omaha Storm Chasers.
Aug 7, 2026RecalledKansas City Royals recalled RHP Mason Black from Omaha Storm Chasers.
Jun 19, 2026OptionedKansas City Royals optioned RHP Mason Black to Omaha Storm Chasers.
May 27, 2026RecalledKansas City Royals recalled RHP Mason Black from Omaha Storm Chasers.
May 5, 2026OptionedKansas City Royals optioned RHP Mason Black to Omaha Storm Chasers.
Apr 19, 2026RecalledKansas City Royals recalled RHP Mason Black from Omaha Storm Chasers.
Mar 17, 2026OptionedKansas City Royals optioned RHP Mason Black to Omaha Storm Chasers.
Nov 11, 2025TradedSan Francisco Giants traded RHP Mason Black to Kansas City Royals for RHP Logan Martin.
Nov 6, 2025Designated for assignmentSan Francisco Giants designated RHP Mason Black for assignment.
Sep 29, 2025RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
Jul 5, 2025OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
Jul 2, 2025RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
Mar 5, 2025OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
Oct 1, 2024RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
Sep 27, 2024OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
Aug 31, 2024RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
Jun 26, 2024OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
Jun 25, 2024RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
May 24, 2024OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
May 17, 2024RecalledSan Francisco Giants recalled RHP Mason Black from Sacramento River Cats.
May 13, 2024OptionedSan Francisco Giants optioned RHP Mason Black to Sacramento River Cats.
May 6, 2024Contract selectedSan Francisco Giants selected the contract of RHP Mason Black from Sacramento River Cats.
Jul 23, 2021SignedSan Francisco Giants signed RHP Mason Black.

Service through 2025 per FanGraphs RosterResource; options and this-season service reconstructed from the MLB transaction log (reconstruction; FanGraphs shows 1). Rule 5 exposure deadline Nov 17, 2026.