When it comes to stocking the Boston Red Sox with pitchers, chief baseball officer Craig Breslow clearly has a preferred profile. That trend became even more apparent this week, as the organization added not one but two towering free-agent arms, each standing at least 6-foot-6. After bringing in 6-foot-8, 225-pound veteran a move that became public Breslow followed up by signing another massive right-hander at 6-foot-6 and 230 pounds.
This latest addition arrives in Boston after spending a season inside one of baseball’s most highly regarded pitching development systems: the Houston Astros. Patrick Halligan, originally selected in the 13th round of the 2021 MLB Draft by the Kansas City Royals, officially signed with the Red Sox on Monday, according to the team’s transactions log, though the move wasn’t posted publicly until Thursday.
Halligan and Guerrero are simply the newest examples of the Red Sox leaning into size and physical presence on the mound under Breslow’s leadership. Analyst Chris Henrique of Beyond the Monster recently pointed out that Boston has also acquired several other large-framed pitchers, including 6-foot-6 left-hander Jake Bennett, obtained from Washington in the Luis Perales trade; 6-foot-5 Rule 5 pick Ryan Watson; and 6-foot-4 lefty Tyler Samaniego, who came over in the Johan Oviedo deal.
Since taking over baseball operations in late 2023, Breslow has consistently targeted imposing arms. He signed 6-foot-6, 245-pound right-hander Lucas Giolito shortly after arriving and later pulled off a franchise-altering trade for 6-foot-6, 245-pound lefty Garrett Crochet in December 2024. The trend continued in the 2024 draft, when Boston selected 6-foot-6, 250-pound left-hander Payton Tolle in the second round. Tolle advanced quickly through the system, making his major league debut in August 2025. Even closer Aroldis Chapman — signed in 2025 — fits the mold, despite being considered relatively smaller at 6-foot-4 and 235 pounds.
Halligan enters the organization following a productive run in the Puerto Rican Winter League with Indios de Mayagüez. Over 22 1/3 innings across 20 appearances, he posted a 2.82 ERA, striking out 30 batters while issuing just six walks, two of which were intentional.
Across his domestic minor league career, Halligan has logged 265 1/3 innings in 146 games, compiling a 4.34 ERA with 282 strikeouts but also 104 walks. The Royals released him in March 2023, after which he was quickly signed by the Atlanta Braves. By 2024, the 26-year-old had climbed to No. 35 on the Braves’ prospect list, according to FanGraphs, before being sent to Houston in April 2025 as a player to be named later in the Rafael Montero trade.
The Astros — renowned for producing pitchers such as Framber Valdez, Hunter Brown, Lance McCullers Jr., Dallas Keuchel and José Urquidy — clearly saw potential in Halligan. That appeal likely centered on his split-finger pitch, which FanGraphs grades as a 70 on the 20–80 scouting scale, placing it firmly in elite territory.
However, Halligan remains a developmental project. According to Ty Anderson of Boston’s 98.5 The Sports Hub, the splitter is essentially his lone standout offering at the moment — a profile that actually aligns well with Breslow’s preference for acquiring imperfect arms and refining them in Boston’s pitching lab.
There are also limitations to note. Halligan’s minor league free-agent deal reportedly does not include an invitation to major league spring training. To begin the season, the Vienna, Virginia native is expected to slot into the Triple-A Worcester bullpen. If his progress earns him a major league opportunity in 2026, the Red Sox would need to create space for him on the 40-man roster.