Christian Koss

SS · R/R · age 28.6 · SF

OCTOBER OK

Roster status
ACTIVE
Service thru 2025
1+000
Service now / projected
1+127 / 1+140
Option years left (2026)
3 (using one in 2026)
Assignments left this season
4 of 5
Contract (2027)
PRE-ARBITRATION / AUTO-RENEWAL
Acquired
Trade (BOS) Mar'24
Outrighted / DFA'd before
0 / 0
Contract
none listed

Next 90 days, by the model

Stays put
71%
Designated
17%
Optioned
7%
Traded
4%
Released or non-tendered
<1%

Pushing the cut risk up: age (28.63) raises it, this season's strikeout rate (0) raises it, last season's xFIP (5.45) raises it.

Context the model does not weigh: ZiPS projects 1.3 WAR, 0.6 WAR this season; 8 IF on the 40-man.

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?

SF returns 15 IF on the 40-man once nobody leaves; about 8 IF jobs survive a normal winter. By his own recent record he ranks 7th among the returners (1.2 WAR against a bar of 0.3), which the calibrated model turns into 93% kept through the tender deadline. Ranked by ZiPS and Steamer instead, which credit his longer track record, he is 9th (0.7 WAR, bar 0.8), worth 95% kept on the same model.

By recent record: returning IFProj. WAR
1. Matt Chapman3.2
2. Rafael Devers2.9
3. Jonah Cox2.2
4. Willy Adames2.1
5. Casey Schmitt1.8
6. Bryce Eldridge1.5
7. Christian Koss1.2
8. Marcelo Mayerlast job0.3
9. Brett Harris0.3
10. Scott Bandura0.1
11. Zach Morgan0.0
12. Jesus E. Rodriguez-0.1
By ZiPS / Steamer: returning IFProj. WAR
1. Matt Chapman3.8
2. Willy Adames3.6
3. Rafael Devers2.9
4. Jesus E. Rodriguez1.4
5. Shay Whitcomb1.1
6. Casey Schmitt0.9
7. Brett Harris0.9
8. Marcelo Mayerlast job0.8
9. Christian Koss0.7
10. Osleivis Basabe0.6
11. Nate Furman0.5
12. Jonah Cox0.4

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, 3 option years left. 4 of the five optional assignments for 2026 remain. A 2026 option year is already used (47 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
202647yesMay 15, 2026 to Jul 1, 2026 (47d)
20256no (under 20)Jun 4, 2025 to Jun 10, 2025 (6d)

Transaction log

Jul 1, 2026RecalledSan Francisco Giants recalled 2B Christian Koss from Sacramento River Cats.
May 15, 2026OptionedSan Francisco Giants optioned 2B Christian Koss to Sacramento River Cats.
Aug 1, 2025Status changeSan Francisco Giants activated 2B Christian Koss from the 10-day injured list.
Jul 1, 2025Status changeSan Francisco Giants placed 2B Christian Koss on the 10-day injured list. Left hamstring strain.
Jun 10, 2025RecalledSan Francisco Giants recalled 2B Christian Koss from Sacramento River Cats.
Jun 4, 2025OptionedSan Francisco Giants optioned 2B Christian Koss to Sacramento River Cats.
Mar 26, 2025Contract selectedSan Francisco Giants selected the contract of SS Christian Koss from Sacramento River Cats.
Mar 27, 2024TradedBoston Red Sox traded SS Christian Koss to San Francisco Giants.
Dec 3, 2020TradedBoston Red Sox traded LHP Yoan Aybar to Colorado Rockies for SS Christian Koss.
Jun 26, 2019SignedColorado Rockies signed SS Christian Koss.

Service through 2025 per FanGraphs RosterResource; options and this-season service reconstructed from the MLB transaction log (reconstruction; FanGraphs shows 3). Rule 5 exposure deadline Nov 17, 2026.