The Red Sox added to their infield mix Wednesday night, agreeing to a one-year, $6-million deal with free agent Isiah Kiner-Falefa, according to multiple reports. The contract includes up to $500,000 in incentives tied to plate appearances and is pending a physical.
Kiner-Falefa, 30, split the 2025 season between the Pirates and the Blue Jays, appearing in 138 games while logging time at three different infield positions. He saw the bulk of his innings at shortstop (817), while also playing third base (211 2/3 innings) and second base (26 1/3 innings).
Boston enters the season with openings at both second and third base following the departure of Alex Bregman, who signed with the Cubs in free agency.
With Kiner-Falefa in the fold, the Red Sox could deploy him primarily at second base, allowing Marcelo Mayer to shift to third while mixing in depth options such as Romy Gonzalez, David Hamilton, Nate Eaton, and Nick Sogard.
The signing aligns with Boston’s offseason emphasis on run prevention after heavily investing in pitching. Chief baseball officer Craig Breslow has been consistent in outlining a defensive-first identity for the 2026 roster.
“I don’t think there’s a question anymore that the identity of our team and the strength of our team is going to be our pitching and our ability to prevent runs,” Breslow said while introducing Ranger Suárez to the Boston media.
“The improvements we made on the pitching side are significant. Going into a game feeling like we can just play our game offensively and on the bases because our pitching is going to keep us in the game is such a huge advantage.”
Boston spent much of the winter connected to higher-profile offensive infielders such as Ketel Marte, Brendan Donovan, Isaac Paredes, and Bo Bichette. Instead, the Red Sox pivoted toward defense, adding a former Gold Glove winner who grades as a plus defender across the infield.
Kiner-Falefa owns strong defensive metrics at second base, posting +12 Defensive Runs Saved and +2 Outs Above Average in nearly 600 career innings at the position, despite most of his experience coming on the left side of the infield.
Offensively, he represents a stark contrast from the bats Boston was linked to earlier in the offseason. The right-handed hitter batted .262 with two home runs, 21 doubles, 40 RBIs, and a .631 OPS in 2025. For his career, Kiner-Falefa carries a .660 OPS with 36 home runs across 918 major-league games.
One notable positive is his contact ability. Kiner-Falefa has struck out at just a 15.7% rate over his career and shows neutral splits against right-handed and left-handed pitching. According to Baseball Savant, he ranks well above league average in bat-to-ball skills, posting an 82nd-percentile squared-up rate while pairing it with a 91st-percentile whiff rate, underscoring how rarely he misses when he swings.
The Red Sox remain active in the trade market, with continued ties to Houston’s Paredes—an ideal Fenway Park fit—and Chicago infielders Matt Shaw and Nico Hoerner.
If Opening Day were today, Boston would likely slot Kiner-Falefa at second base and bat him toward the bottom of the lineup. Against left-handed pitching, Gonzalez could still see the bulk of the at-bats, with Kiner-Falefa sliding to third base on days the club opts to shield Mayer from same-handed matchups.
One clear positive of adding Isiah Kiner-Falefa is his ability to anchor shortstop if Trevor Story were to miss time due to injury. Kiner-Falefa has appeared in 450 career games at the position, more than any other player currently on the roster. While Boston could opt to slide Mayer to shortstop in that scenario, doing so would immediately create a new question at third base—one the Red Sox are now better positioned to avoid.
The addition of Kiner-Falefa allows the Red Sox to lean further into their athleticism. His positional versatility gives Boston added flexibility across the infield, while his ability to swipe bases adds another layer of value beyond defense.
Boston remains left-handed heavy in the outfield, with Jarren Duran, Roman Anthony, and Wilyer Abreu all competing for regular playing time. The Red Sox are holding Duran and Abreu in high regard, making a trade unlikely unless a team meets their demands. Ceddanne Rafaela, who won a Gold Glove in center field last season, is expected to play every day and could theoretically factor into the infield at second base. However, the Red Sox have remained adamant that they want Rafaela to stay in the outfield moving forward.
The Sox have continued to explore adding another right-handed bat, particularly one who could serve as a potential replacement for Rob Refsnyder in a platoon role. Among the remaining free-agent outfielders, Randal Grichuk, 34, stands out after posting an .857 OPS against left-handed pitching over the last three seasons. The Red Sox have been consistently linked to Grichuk recently under Breslow, making him a familiar and logical fit should the club add another right-handed option.
Kristian Campbell represents another right-handed hitting option, but the organization views him as an everyday player. As a result, he appears destined to open the season with the WooSox to ensure he receives consistent at-bats rather than being deployed in a part-time role.