The Rockies once again have a left-handed reliever problem.

They went through 2020 with barely a lefty, sometimes without one at all. But this paucity led to a discovery -- right-hander Tyler Kinley handled them well, to the tune of a .111 batting average.

But with the bullpen still thin from the left, Kinley’s magic hasn’t carried into 2021. That -- and Johnny Cueto’s 8 2/3, four-hit innings -- hurt on Friday afternoon in a 3-1 loss to the Giants at Oracle Park.

Left-handed starter Austin Gomber shook off a disappointing debut on Sunday to border on dominant for the first six innings on Friday. But manager Bud Black went to Kinley in the seventh, knowing he would be facing key lefties. Kinley walked pinch-hitter Alex Dickerson, then gave up a Brandon Crawford two-run double that proved the difference.

Though the Rockies have been light from the left side of the ‘pen since last year, they did not add an established southpaw during the offseason. This year, rookie Ben Bowden -- who fanned Mike Yastrezemski after Kinley was lifted -- made the Opening Day roster. Phillip Diehl did not pitch well enough in Spring Training to make the team; the other lefty relievers on the roster are Lucas Gilbreath and Brian Gonzalez, neither of whom have pitched in the Majors.

It’s early, but lefty batters are 5-for-11 with two doubles and a triple against Kinley, who walked two and gave up the go-ahead hit in one-third of an inning on Friday.

“Tyler has had a lot of success against lefties in his career,” Black said. “Let's see how this entire season plays out at the end of the year. I know we have to make adjustments, short-term, when we see inadequate performance, but these guys are going to pitch -- hopefully, if they stay healthy and perform -- 55-70 games.

“I think Tyler's been in four games. So there's a lot of games left for him to contribute. But I still have a lot of faith in his slider against both left and righties. I still have a lot of faith in his fastball with that velocity against both lefties and righties. Today, he didn't have it as far as his control.”

Gomber, the Major Leaguer among the four players the Rockies acquired from the Cardinals for third baseman Nolan Arenado, rebounded from seven walks in three innings against the Dodgers at home to go 6 1/3 frames on Friday and give up just one hit while striking out five. He vowed on Sunday to push his debut struggles out of his mind.

“It was behind me the day I woke up on whatever the day after it was,” Gomber said. “It happens. Obviously, it's not ideal. But the next morning, it was all about San Francisco and what I could do today to try to give our team the best chance to win, and it'll be the same thing [going forward] -- I'll wake up tomorrow, and it'll be I think my next start against the Dodgers.”

The Rockies weren’t hitting Cueto, who stayed out of the middle of the plate, although Colorado questioned several pitches. Charlie Blackmon, respected for his knowledge of the zone, drew an ejection from plate umpire Ben May for his forceful inquest of a third-strike call in the seventh inning.

But the matchup with Cueto, who saw little trouble until pinch-hitter Chris Owings’ leadoff triple in the ninth, excited Gomber.

“It was fun,” Gomber said. “He threw the ball really well, I thought I threw the ball well. Unfortunately, somebody's got to lose, and we just weren't able to come through.

But Gomber issued two of his four walks in the seventh before Kinley replaced him. He said the leadoff walk to Darin Ruf came from “not giving in.” The one-out walk to Buster Posey, however, he lamented.

“I'm definitely not trying to walk the guy there. I'm trying to get the ground ball to get a double play, get out of the inning. It's unfortunate. You never want to walk guys.”

The Rockies’ staff finished with seven walks, with Gomber’s in the seventh problematic and Kinley’s more troublesome.

The scarcity of lefties is a roster structure issue. However, the pitcher’s handedness doesn’t matter if he isn’t hitting the strike zone.

“Just talking pitching, you have to get the ball over the plate,” Black said.