Giants manager Bob Melvin will find himself in an unusual position as he ponders his starting lineup for Saturday night’s rematch with the Athletics in San Francisco.

What do you do with a guy who hit three home runs in the previous night?

That’s what Wilmer Flores did in the series opener, smacking a grand slam, a three-run blast and a solo shot to account for eight of the Giants’ runs in a 9-1 triumph.

Flores will begin play Saturday as the major-league co-leader in RBIs, having caught New York Yankees captain Aaron Judge with his career-best performance Friday.

Asked afterward if he’d found himself a new guy to hit behind leadoff man Heliot Ramos, Melvin admitted he’s not sure.

“We’ll see how it goes tomorrow,” he said with some uncertainty.

Flores has batted in every lineup spot except leadoff this season. Friday’s start in the second position was just his third of the season.

He’s had a majority of his at-bats in the No. 5 (21 starts) and No. 8 spots (13 starts), the latter having been his usual home against right-handed pitchers like Luis Severino (1-4, 4.70 ERA), the Athletics’ scheduled starter on Saturday.

“I don’t know that anybody could have predicted this,” Melvin said of a season in which Flores, coming off an aborted 2024 due to a right-knee injury, leads the Giants in RBI and home runs with 10.

Melvin said the club has been searching for a new No. 2 hitter after Willy Adames hit just .217 there in 41 starts this season.

“He’s done some pretty good damage there,” Melvin said of Flores, whose grand slam Friday came off A’s left-hander JP Sears. “It just seemed natural (to slot Flores second against the lefty).”

Severino has dominated his lifetime matchups with Flores, holding him hitless in seven at-bats with three strikeouts.

The 31-year-old has made just two career starts against the Giants, going 0-1 with a 2.77 ERA while allowing just seven hits in 13 innings with 11 strikeouts.

Severino will be attempting to snap an A’s pitching slump. Their starters have allowed 14 runs and 18 hits in 11 innings over the last three games, which the A’s have lost 9-3, 19-2 and 9-1.

A poor showing by Osvaldo Bido in Los Angeles on Thursday got him demoted to the minors, a decision A’s manager Mark Kotsay surprisingly explained as having been impacted by the club’s competitive start this season.

“Last season, we were a lot more patient in making moves like this,” said Kotsay, whose club improved by 19 wins last year, setting up a potential postseason pursuit this year. “This season, our mindset is different.”

Right-hander Landen Roupp (2-3, 4.95) is scheduled to start the rematch for the Giants. He has never faced the A’s in his two-year, major league career.

The Giants have lost Roupp’s last three starts, in which he’s allowed eight earned runs in 14 1/3 innings.

–Field Level Media