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With the addition of Corban Joseph to the A’s, Jurickson Profar is being pushed far into the background. And it’s official: Before Wednesday’s 9-5 win over the Giants at Oracle Park, manager Bob Melvin spoke to Profar about his greatly reduced role.

Profar, Oakland’s primary second baseman most of the season, understands the decision.

“I don’t feel like I’ve been contributing like I’m capable of, so I’m OK with it,” Profar told The Chronicle. “I’ll just keep working and try to find it.”

Joseph, who was batting .371 at Triple-A Las Vegas, singled in the eighth inning and hit a sacrifice fly in the ninth in his first appearance with Oakland.

“I’ve been working the count really well, battling and not really giving many at-bats away,” Joseph said. “That’s something I really take pride in.”

Joseph also has played first, third and left — he has even pitched an inning — in his career, but Melvin said for now Joseph will get his chance at second, at least against right-handers.

“We’re maybe not getting as much production as we want at that position, so maybe you look somewhere else,” Melvin said.

Profar is batting .205, and his on-base percentage is .268. He also has struggled with his throwing all year, and his minus-7.3 SABR defensive index ranking is the worst in the majors.

He’s a switch hitter, and with the arrival of Joseph, a left-handed hitter, Profar will be reduced to playing against left-handed starters — if that. Chad Pinder could wind up playing the position against lefties on occasion, too.

The A’s are a little light in left-handed hitters, one consideration in bringing up Joseph, but Joseph also earned his shot. Melvin said he’d been among those to peg Joseph as minor-league depth, and he applauded the work Joseph did to push himself to the fore.

“He’s put himself in this position,” Melvin said.

The year has been a disaster for Profar — and for the A’s, who acquired him in a three-way deal in which they sent reliever Emilio Pagan to Tampa Bay and minor-league infielder Eli White to Texas. Profar was coming off a year in which he hit .254 with 20 homers and 77 RBIs.

“My swing doesn’t feel like it did last year,” Profar said. “I’ve just been grinding every at-bat, trying to help any way I can. I’m going to keep working hard, and when I get the chance, I’m going to try to deliver for the team.”

Profar is under team control for another year, though it’s unlikely he’s much in the A’s plans with Triple-A infielder Jorge Mateo out of options next spring and pushing for a big-league spot.

It’s unclear how much interest there might be in Profar, given his throwing problems, but his age (26) and his high-profile status in the past as a minor-league prospect might help should Oakland hope to trade him. And though his average and on-base percentages are dismal, Profar does have a knack for producing at the right time; he has driven in 51 runs and scored 45 in 105 games this season.

With Joseph’s promotion, outfielder Nick Martini was optioned to Las Vegas, and catcher Beau Taylor was designated for assignment to get Joseph on the 40-man roster. Taylor, 29, is highly regarded by the A’s coaches and development staff, and he’d done well in some brief big-league time.

“Very tough,” Melvin said of the decision. “Hopefully he clears waivers. I’ve got my fingers crossed on that one. Beau is really a guy we’d like to keep.”

Catching prospect Sean Murphy is about to return to Las Vegas after missing two weeks with knee soreness.

Susan Slusser is a San Francisco Chronicle staff writer. Email: sslusser@sfchronicle.com Twitter: @susanslusser