CHICAGO — Kyle Harrison was never himself during spring training, tasked with recovering from both a nagging shoulder injury and an illness-induced weight loss. Thus, he didn’t make the team out of spring training. But a month into the season, Harrison is back up with the Giants.

As a reliever.

“Definitely something new, but I’m going to embrace it,” Harrison said. “I’m here for a reason. I want to help this team win. They thought this is the best way I could help this team win and I agree right now. We’re going to go have fun in the bullpen and get guys out.”

Harrison, who was recalled after Sunday’s 9-3 win, begins his time as a reliever with almost no bullpen experience as a professional. The left-hander has never pitched out of the bullpen in the majors and has only done so three times in the minors, all three appearances coming in 2022. Manager Bob Melvin said Harrison won’t have a specific role and that “anything’s kind of on the table for him.”

“If we need him for an inning, it’s going to be an inning. If we need him for three, it’s going to be three. He’s open to all that,” Melvin said. “We haven’t told him any specifics about, ‘This is when you’re going to be in the game’ basically like we did with Hayden (Birdsong). There could be some of that. It just depends on what the bullpen looks like on a particular day.”

Harrison isn’t the only 23-year-old starter who’s currently in San Francisco’s bullpen.

Birdsong, who started 16 games last season as a rookie, cracked the Opening Day roster as a reliever and dominated in the role, posting a 1.00 ERA with 19 strikeouts over 18 innings. Melvin described having two young starters in the bullpen as “very unusual,” adding that Birdsong’s success was a factor in Harrison’s promotion.

“I’ve been in his ear here and there,” Harrison said of Birdsong.

Harrison entered spring training with incumbent status after ranking second on the Giants last season in starts (24) and innings (124 1/3), but he was never truly in the competition for the final rotation.

Along with trying to fully recover from last year’s left shoulder injury — an ailment that impacted his mechanics in conjunction with an ankle injury — Harrison got sick a week before spring training and lost roughly 15 pounds. The Giants, in response, delayed Harrison’s spring debut.

When Harrison did take the mound, he allowed eight runs over 6 2/3 innings of Cactus League play, his velocity noticeably dipping in the process. The Giants optioned him to Triple-A Sacramento in late-March, saying he was behind in his build up.

With the River Cats, Harrison found the success that eluded him in spring training. Over six starts with Triple-A Sacramento, Harrison posted a 3.46 ERA and 2.95 FIP (fielding independent pitching) over 26 innings. Harrison’s strikeout rate spiked as well. At the time of his promotion, his 38 strikeouts led the Pacific Coast League, one ahead of teammate Carson Seymour.

Along with the results, Harrison has regained the lost weight and strengthened his shoulder. That improved health has been most apparent in his velocity, which has ticked up from the low-90s during spring training to the mid-90s in April:

Along with the velocity, Harrison has gotten more vertical movement on his four-seam fastball by raising his arm angle.

“It’s great to see. I haven’t seen that in a while,” Harrison said. “Going back to the shoulder thing, that was the frustrating thing where I just couldn’t get over that hump. Mechanics were bad. Just really took that month and change in Sacramento to feel right and implement those routines and get the arm height up.”

Added Melvin: “Spring training was kind of uneven for him. Now, you’re looking up (at the scoreboard) and not seeing the numbers that you want to see. He was very understanding and patient with the fact that it was probably going to take a little while for it to come back. The last few times out, it has.”

To make room for Harrison, the Giants designated reliever Lou Trivino for assignment.