Will Red Sox protect Christian Koss from Rule 5 Draft by adding him to 40-man roster?

Among qualified Eastern League hitters, Koss ranked fourth in hits (125), third in RBIs, 11th in runs scored, 19th in stolen bases, 18th in batting average, 16th in speed score (6.5). He also ranked 35th in strikeout rate (25.8 percent), 57th in walk rate (4.7 percent), 43rd in on-base percentage, 35th in wRC+ (99), 60th in line-drive rate (14.4 percent), 57th in groundball rate (48.9 percent), and 48th in swinging-strike rate (14.7 percent), per FanGraphs.

Defensively, Koss saw playing time at five different positions in 2022. The 6-foot-1, 182-pounder logged 214 1/3 innings at second base, 185 innings at third base, 601 2/3 innings at shortstop, nine innings in left field, and 37 innings in right field. This year marked the first time he had ever played the outfield in his professional career.

Koss’ pro career dates back to June 2019, when he was selected by the Rockies in the 12th round of the amateur draft out of the University of California, Irvine. The Red Sox acquired the Riverside native from Colorado in exchange for left-hander Yoan Aybar the following December.

The Red Sox made that trade in order to clear a spot on their 40-man roster. Koss now finds himself in a similar position. As noted by MLB Pipeline, what makes Koss appealing is the fact that he “has solid raw power and speed, not to mention a high baseball IQ.” At the same time, however, Koss’ high strikeout rate and low walk rate indicate that “his lack of plate discipline could be a problem at higher levels” of the minor-leagues.

Koss, who turns 25 in January, is currently regarded by MLB Pipeline as the No. 20 prospect in Boston’s farm system. The former Anteater has spent his offseason playing for the Criollos de Caguas of the Puerto Rican Winter League. There, he has been under the watchful eyes of Red Sox first base coach Ramon Vazquez (Caguas’ manager), WooSox bench coach Jose Flores (Caguas’ infield coach), and Red Sox manager Alex Cora, who hails from Caguas.

If the Red Sox were to add Koss to their 40-man roster by next Tuesday’s deadline, they would retain his rights moving forward. In that scenario, Koss would be in line to make the jump to Triple-A Worcester while providing Boston with infield and outfield depth in 2023.

If the Red Sox do not add Koss to their 40-man roster by November 15, another club could acquire him for $100,000 during next month’s Rule 5 Draft. That team would then be responsible for carrying Koss on their major-league roster for the entirety of the 2023 season. If they were unable to do so, Koss would have to be offered back to the Red Sox for $50,000.