SAN FRANCISCO -- Back in Spring Training, manager Gabe Kapler received a rare bottle of whiskey from new Giants reliever Luke Jackson.

Kapler told Jackson he would save the gift for when the 31-year-old right-hander completed his long road back from Tommy John surgery. That day finally arrived on Wednesday afternoon.

One day after being activated off the 60-day injured list, Jackson struck out two over a scoreless inning in his first Major League appearance since Oct. 30, 2021, emerging as one of the few bright spots in the Giants’ 9-4 loss to the Pirates at Oracle Park.

“You feel like rehab is never going to end, and then you finally get out here, and it’s a little bit surreal, I guess,” said Jackson, who was sipping his celebratory drink after the game. “I felt good. I wish we could have gotten a win today. It would have been a lot better. But it was fun to get back out there and be back with the guys.”

Wednesday’s defeat dropped the Giants to 17-12 in May and 28-28 overall, snapping the club’s streak of four consecutive series wins this month. Left-hander Alex Wood took the loss after giving up six runs on eight hits -- both season highs -- over 4 1/3 innings in his eighth appearance of the year. 

Jackson entered the game in the top of the seventh and retired Ke’Bryan Hayes on a lineout to right field before striking out Jack Suwinski and Chris Owings on sliders to end his 11-pitch Giants debut. He topped out at 96.3 mph on his fastball and induced two swinging strikes on eight sliders. 

“Perfect,” Kapler said. “It couldn't have been better. Efficient, clean. Not too many pitches. He didn’t have any of those moments where you felt like you might have to get him out of the game. It went as smooth as we could have imagined. Obviously, it was a nice landing spot for him.”

Jackson didn’t pitch last year after undergoing Tommy John surgery in April 2022, but he enjoyed a career-best season for the World Series champion Braves in 2021, logging a 1.98 ERA with 70 strikeouts over 63 2/3 innings.

The Giants signed him to a two-year, $11.5 million deal in January, hoping the veteran would help stabilize the back end of their bullpen along with fellow free-agent addition Taylor Rogers.

Jackson made six rehab appearances between Single-A San Jose and Triple-A Sacramento, allowing four runs on four hits over 5 1/3 innings, though the Giants have expressed confidence in his ability to handle high-leverage spots now that he’s healthy.

“We’re not going to have any issues having Luke pitch in big moments for us going forward,” Kapler said.

Jackson’s return coincided with an impressive run by the Giants’ bullpen, which leads the Majors with a 1.00 ERA over 72 1/3 innings since May 15. Jackson wasn’t surprised to see the unit turn it around after a rough April and said he’s eager to settle in and hopefully help his fellow relievers sustain their success. 

“The past two and a half weeks, these guys have been playing great baseball,” Jackson said. “I think you see the potential of this team. Getting everyone back and healthy, we’re almost there. I think once the train gets moving, it’s going to be a fun team to watch.”