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Alex Cora of the Boston Red Sox sits in the dugout.

When it comes to adding pitchers to the Boston Red Sox organization, chief baseball officer Craig Breslow has a type. That fact only became more clear this week when, not once but twice, the club signed a free agent hurler who stands at least 6-foot-6. After acquiring 6-foot-8, 225-pound veteran minor leaguer Tayron Guerrero, whose signing was publicly revealed last Saturday, Breslow struck again with a 6-foot-6, 230-pound right-hander.

But this pitcher comes to Boston after a year in one of the most respected pitching development systems in the game, the pipeline run by the Houston Astros.

Patrick Halligan, a 13th-round Kansas City Royals draft pick in 2021, signed with Boston on Monday, according to the official Red Sox transactions ledger, though the acquisition does not appear to have been posted there until Thursday.

Halligan Joins XXL-Sized Red Sox Pitching Corps

Halligan and Guerrero are just the latest pair of big-bodied pitchers acquired by the Red Sox under Breslow.

“Newly acquired left-hander Jake Bennett (6-foot-6), who came over from Washington in the Luis Perales trade, Rule 5 pick Ryan Watson (6-foot-5), and left-hander Tyler Samaniego (6-foot-4), acquired in the Johan Oviedo deal, are recent examples of Boston prioritizing size and physicality on the mound,” wrote analyst Chris Henrique of Beyond the Monster.

Shortly after taking the reins in Boston in late 2023, Breslow signed 6-foot-6, 245-pound right-hander Lucas Giolito. Then in December 2024, in a deal that changed the trajectory of the Boston franchise, Breslow traded for 6-foot-6, 245-pound left-hander Garrett Crochet.

Then, in the second round of the 2024 draft, Breslow and the Red Sox selected 6-foot-6, 250-pound left-hander Payton Tolle, who progressed so quickly that he made his big league debut in August 2025 — and in 2025 signed free agent closer Aroldis Chapman, who can be seen as relatively small at 6-foot-4, 235 pounds.

Halligan Boasts Elite-Level Split-Finger Pitch

The Red Sox signed Halligan coming off a 20-game stint with Indios de Mayagüez of the Puerto Rican Winter League, where he put together an impressive 2.82 ERA in 22 1/3 innings, striking out 30 while walking just six, two intentionally.

In 146 domestic minor league games and 265 1/3 innings, Halligan has a respectable, if not extraordinary, 4.34 ERA with 282 strikeouts against an unsettling 104 walks. The Royals released Halligan in March 2023, and he was quickly picked up by the Atlanta Braves. By 2024, the now-26-year-old rose to the No. 35 spot in the Braves’ prospect rankings, as calculated by FanGraphs.

But the Braves in April 2025 shipped Halligan to the Astros as a player to be named later in a trade for Rafael Montero.

The Astros — whose pitching pipeline has turned out such big league stars as Framber Valdez, Hunter Brown, Lance McCullers Jr., Dallas Keuchel, José Urquidy and many others — saw something in Halligan, apparently.

What they saw was likely his split-finger pitch, which FanGraphs grades at 70 on the 20–80 scouting scale.

Red Sox Could Make Halligan a Project

The new Red Sox right-hander’s splitter is “pretty much the only weapon of note in Halligan’s arsenal as of right now,” according to Ty Anderson of Boston’s 98.5 The Sports Hub. “That’s the kind of stuff that the Red Sox almost like to hear, though, with Breslow and the Red Sox seemingly always eager to get an imperfect pitcher in their proverbial pitching lab for tweaks.”

But there are some cautionary notes accompanying the Red Sox signing of Halligan. His minor league free agent contract reportedly did not include an invitation to major league spring training, as such contracts often do. To start the season, at least, the Vienna, Virginia, native will join the bullpen corps at Triple-A Worcester.

If the Red Sox see enough in Halligan’s development to call him up for his major league debut anytime in 2026, they will have to clear a spot on the team’s 40-man roster to fit him in.

Jonathan Vankin JONATHAN VANKIN is an award-winning journalist and writer who now covers baseball and other sports for Heavy.com. He twice won New England Press Association awards for sports feature writing. He was a sports editor and writer at The Daily Yomiuri in Tokyo, Japan, covering Japan Pro Baseball, boxing, sumo and other sports. More about Jonathan Vankin