Thursday marked the deadline for the Red Sox to activate nine players from the 60-day injured list, and with only eight roster spots available the club needed to make a move to clear space.

Luis Guerrero wound up being the odd man out.

The Red Sox announced Thursday afternoon that they have designated Guerrero for assignment, potentially signaling the end of the hard-throwing right-hander’s time with the organization.

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Guerrero, 25, has appeared in 22 MLB games over two seasons and posted a 2.63 ERA over 27.1 career innings. He debuted in September of 2024 and did not allow an earned run in his first nine MLB outings, putting himself in strong position to make the Opening Day roster the following spring.

But Guerrero did not capitalize on his opportunity. The righty struggled with his command and wound up only appearing in 13 MLB games this past season, posting a 4.15 ERA with 14 walks in 17.1 innings. He was placed on the IL with a right elbow strain on June 28 and did not pitch again.

Guerrero was among the nine players on the 60-day IL who the Red Sox had to activate. The others were right-handers Kutter Crawford, Hunter Dobbins, Tanner Houck and Josh Winckowski, left-hander Patrick Sandoval, infielders Vaughn Grissom and Marcelo Mayer, and first baseman Triston Casas.

The club’s 40-man roster is now at 40.

Extra innings

Hunter Dobbins, who emerged as a key arm for the Red Sox as a rookie this past season before suffering a season-ending ACL tear on July 11, announced on Twitter this week that he has been cleared to start his full throwing program. The right-hander is now in Fort Myers and posted a first-person video of himself playing catch Thursday. … Two Red Sox minor leaguers have been selected as Arizona Fall League “Fall Stars,” those being right-hander Luis Perales and infielder Stanley Tucker. Perales is one of Boston’s top pitching prospects but will not participate in the game because he is still ramping up after completing his recovery from Tommy John surgery.