Red Sox Breakout Rookie Must Inherit Kenley Jansen's Job, Insider Says

It's time to test out the succession plan...

Jun 30, 2024; Boston, Massachusetts, USA; Boston Red Sox pitching coach Andrew Bailey (53) talks with relief pitcher Justin Slaten (63) in the seventh inning against the San Diego Padres at Fenway Park. Mandatory Credit: David Butler II-Imagn Images / David Butler II-Imagn Images

The ninth inning for the Boston Red Sox is about to have a whole new look.

Future Hall of Famers are tough to come by, and the Red Sox have had one in their closer's role the past two seasons. But Kenley Jansen was placed on the injured list on Sunday with shoulder inflammation, likely signaling the end of his Boston career.

Jansen was brought in to stabilize the ninth inning for the Red Sox, and despite all the other things that were unstable about the team during his tenure, he succeeded. He saved 56 of 64 save opportunities in a Red Sox uniform while pitching to a 3.44 ERA in 94 1/3 innings.

With Jansen heading to free agency, the closer's role for 2025 is up in the air. Liam Hendriks won't pitch this season and Chris Martin is a free agent too, but rookie Justin Slaten, who the Red Sox stole from the New York Mets last winter, could be the homegrown closer Boston sorely needs.

Jen McCaffrey of The Athletic made the pitch for giving Slaten all the remaining save opportunities this season.

"Cora said he will use Chris Martin and Justin Slaten for save opportunities this week, but it seems wise to give Slaten all of the chances. His closer potential is obvious and something the Red Sox have suggested throughout the season," McCaffrey said.

"Liam Hendriks is signed through next year, but not guaranteed to take the closer role. Hendriks hoped to make it into a game by the end of this season as he works his way back from Tommy John surgery, but time is running out. Slaten would benefit from the exposure."

Slaten, who turned 27 on Sept. 15, has a 3.04 ERA/2.62 FIP in 53 1/3 innings this season. He's excelled in multi-inning situations and also become adept at getting out of jams in high-leverage spots.

A key aspect of the Red Sox bullpen's second-half collapse was losing Slaten to the injured list with right elbow inflammation. They were in Wild Card position and nine games over .500 when he left, and just three games over .500 by the end of the day he returned.

Being a closer, though, is a different animal than succeeding in any other relief role. The last three outs of the game are the toughest ones to get, which is why closers as good as Jansen get paid almost as much as starters.

We don't yet know how Slaten will perform in a full-time closer's role. But hopefully, a week is enough time to get some information.