It seems Kenley Jansen’s season, and his time in Boston, have come to an end.

Hours after the veteran closer took the mound to seal an 8-1 Red Sox victory in the first game of Sunday’s split doubleheader with the Minnesota Twins, his manager announced that he was likely going to be placed on the injured list on Monday.

“He’s been dealing with the shoulder and recovering is not (happening) right now for him. He’s been struggling with that,” Alex Cora said following his team’s 9-3 victory in the second game. “There’s a good chance he’ll go on the IL tomorrow, and we’ll move on.”

Jansen dealt with various ailments and struggled at times throughout the 2024 season, but ended up putting up better numbers than last year. Coming off a 2023 in which he posted a 3.63 ERA and 1.28 WHIP over 51 appearances totaling 44 2/3 innings, he finishes 2024 with a 3.29 ERA and 1.06 WHIP over 54 appearances totaling 54 2/3 innings. In both seasons, he blew four saves.

In Jansen’s absence, Cora said the Red Sox plan to “mix and match” with veteran Chris Martin and rookie Justin Slaten.

Martin, 38, has been an incredible addition to the bullpen since signing with the club before last season. He’s worked primarily as Jansen’s setup man, but has closed out games as well, including stepping into the closer role last fall when Jansen’s 2023 campaign ended in mid-September. This season, Martin owns a 3.48 ERA over 42 appearances, including eight games finished. He finished 12 games last season out of 55 total outings.

Slaten, who turned 27 last week, has also made 42 appearances this year, including 15 of four outs or more, and seven games finished. He’s held opponents scoreless in 30 outings, and only allowed multiple runs four times, all before the All-Star break. He’s allowed more than two earned runs just once.

After two seasons in Boston, Jansen and Martin are both headed for free agency this winter. The Sox skipper hinted that the Red Sox envision Slaten, who won’t hit free agency for more than half a decade, as a potential long-term closer option.

“I think it’s an opportunity for both of them to get, be the closer,” Cora said. “Be good for Slaten to kind of, like, get his feet wet in that role.”