‘Good chance’ Kyle Harrison is done for the year after SF Giants place left-hander on IL with shoulder inflammation

SAN DIEGO — With three weeks to go in the regular season, Kyle Harrison may have thrown his last pitch of 2024.

The Giants placed the rookie left-hander on the injured list Friday, and manager Bob Melvin said there’s “probably a good chance” he will eventually be shut down for the season, given the time constraints to get back into game shape by the time his 15 days are up.

After Harrison was hit around in his last start, Melvin took him aside and after their conversation, the 23-year-old underwent imaging that revealed some mild inflammation in his left shoulder. While there was no evidence of structural damage, it was enough to prompt potentially a season-ending IL stint.

“He tries to push through things – he’s a tough kid – but after the last start, I sat down with him, and he admitted it was probably bothering him a little bit more the last time,” Melvin said before the Giants started a three-game series against his former club.

Harrison won’t be eligible to be activated until September 19, when the Giants will have 10 games left on their schedule, and will not throw until he is reexamined in the next week, according to the club. He did not travel with the team to San Diego, so Melvin was left to discuss the specifics.

The skipper said Harrison had been experiencing discomfort in his shoulder “off and on for a little bit” and attributed his diminished velocity to it. In his last start Tuesday against the Diamondbacks, Harrison lasted a career-low 2⅔ innings while allowing six runs, topping out at 93 mph and registering three fastballs below 90 mph.

“I think that’s all kind of getting through this season,” Melvin said. “Identifying what he needs to do as far as building himself up, get a little stronger maybe. But going through what he did this year, you wear down a little bit. I think that’s kind of what happened toward the end.”

If that’s it for the San José-born graduate of De La Salle (Concord), he will finish his rookie season 7-7 with a 4.56 ERA, 118 strikeouts, and 42 walks in 24 starts and 124⅓ innings.

At times, he flashed the potential that made him the top left-handed pitching prospect in the game when he debuted last August, such as his seven shutout innings at Coors Field in May or the 11 strikeouts he racked up against the Rockies in his final start of July.

But since the start of August, after the Giants placed their bets in him to make up one-fifth of their “best rotation in baseball,” as termed by the president of baseball operations, Farhan Zaidi, they won only two of his six starts, while he posted a 7.76 ERA and allowed opponents to bat .303 against him. Of bigger concern was their success against Harrison’s bread-and-butter four-seam fastball.

The home run he allowed to Randal Grichuk in the first inning of Tuesday’s loss was the sixth time opponents took his heater deep since the start of August. He averaged 91.2 mph on 35 fastballs in his final start, down from 93.9 in his first start of the year, 94.4 when he debuted last August, and 94.9 at the peak of his minor-league career.

“There have been times he’s been effective with (lower velocity),” Melvin said. “It certainly will play a lot better for him if it’s a little higher.”

If it sounds familiar, well, the Giants already had one starting pitcher on the injured list with shoulder inflammation after showing a drop in velocity and effectiveness as he surpassed his previous career-high in innings. Jordan Hicks said he was suffering from full-body fatigue in his first full season as a starter, and Melvin didn’t rule out the possibility that Harrison hit a wall, too.

“He’s trying to finish the season and push through,” Melvin said. “There are going to be times where you don’t feel great. Other times it becomes a concern, and I think it finally got to that point with him.”

Harrison’s previous career-high in innings came in 2022 when he threw 113 between High-A and Double-A, and he tossed 102⅓ in 2023 as a baseline for this year. Hicks blew past his previous career-high of 77⅔ as a rookie in 2018 and last year’s total of 65⅔ by even more with 108⅓ in 28 games (20 starts) this season.

Hicks said he would like to return and finish strong, and he’s taking steps toward that goal with a bullpen scheduled for Saturday. Likewise, Robbie Ray (hamstring) will join him on the bullpen mound at Oracle Park and looks poised to rejoin the Giants’ rotation before the end of the season.

As for Harrison’s newly vacant rotation spot, the Giants are still determining how to cover it.

They recalled right-handed reliever Austin Warren from Triple-A Sacramento to take Harrison’s roster spot and lend a hand to a bullpen that has pitched at least six innings in each of their past three games — 20 frames in total — and with Mason Black starting Friday in Ray’s spot, one potential option is already off the board.

Harrison’s next scheduled turn in the rotation would be Sunday, in the final game of their series in San Diego, but the Giants listed that slot as TBD when they announced Black and Logan Webb as their probable starters for the first two games of the series.

“We’ll see how we get there,” Melvin said. “Our bullpen’s been beat up a little bit. We’ve had to cover a lot of innings for a while now. So we’ll see how we get there, if we do it internally or have to do something different. A lot will be ironed out after today and tomorrow.”