SAN FRANCISCO — Justin Verlander took another step in his return from right pectoral soreness on Friday, throwing a live bullpen in the range of 35-40 pitches prior to the Giants’ night game against the Atlanta Braves.

Manager Bob Melvin said the Giants will see how Verlander felt Saturday and determine the next steps. Melvin said Verlander, who has a 4.33 ERA with 41 strikeouts over 10 starts, would “have to feel really good (Saturday)” to start the next time his turn in the rotation comes up, which could be on Tuesday against the Colorado Rockies in Denver. That creates the possibility that Verlander returns to the mound next weekend at Dodger Stadium.

Verlander was placed on the 15-day injured list on May 22, retroactive to May 19.

Kyle Harrison, who is currently replacing Verlander in the rotation, was set to throw a bullpen session Saturday after being diagnosed with a left elbow contusion due to being struck by a ground ball in his past start. Harrison told reporters that he feels good after receiving treatment.

Harrison is lined up to start on Tuesday when the Giants begin their three-game set against the Rockies. Harrison has made three starts since Verlander hit the injured list, posting fine outings against the Washington Nationals and Miami Marlins before allowing five runs to the San Diego Padres.

Harrison stands to return to the bullpen as a multi-inning reliever assuming Verlander is set to return from the injured list. Despite ranking second last year on the Giants in starts (24) and innings (124 1/3), the 23-year-old Harrison stands to spend a good chunk of this season in the bullpen.

Harrison had never pitched as a reliever in the majors prior to this season. He allowed two earned runs over 5 1/3 innings in four appearances out of the bullpen. The team still views Harrison as a starter long-term and Melvin said things will be “fluid” with Harrison, acknowledging the difficulty of balancing Harrison’s development and the needs of the team.

“One thing I do know is you’re not going to have five or six starters over the course of the season,” Melvin said. “When Verlander’s back in, that obviously could potentially be the move. There’s still some room for a length lefty, but that’s something we’re going to have to be cognizant of over the course of the season: make sure he gets some innings in to be prepared to do what we expect him to do for a long time.”

Adames scheduled for an off day

Shortstop Willy Adames, who had played in all 63 of the Giants’ games this season entering Friday, will receive a scheduled off day this afternoon. With the Giants off on Monday, Adames will get back-to-back rest days.

Melvin did not formally announce who will start in Adames’ place today, but added that infielder Casey Schmitt is currently the Giants’ backup shortstop. This season, Schmitt has spent time at first, second and third base.

“(Schmitt) is the backup shortstop; don’t tell him,” Melvin said with a laugh.

Adames has been one of baseball’s most durable players over the last half-decade, averaging 147 games from 2021-24. But he stands to benefit from a mental reprieve given his offensive struggles.

The 29-year-old entered Saturday with a .195 batting average with five home runs and a .591 OPS after signing a seven-year, $182 million contract this offseason, the largest deal in franchise history. Along with the cold bat, Adames has rated out as a below-average defender (-8 defensive runs saved).

President of baseball operations Buster Posey preached patience last week when discussing Adames’ lack of productivity on KNBR’s “Murph and Markus.”

“It’s all about them kind of finding their groove, and it’s our job to be patient,” Giants hitting coach Pat Burrell told this news organization last month. “Keep working, keep believing, and letting these guys find their way. Willy is super talented. He’s got a track record that shows it. He’ll be fine.”

Ball thrown by fan causes confusion

There isn’t much that Melvin hasn’t seen on a baseball field. Friday night provided him — and most of his players — with a first.

In the top of the fourth inning, Sean Murphy hit a bases loaded line drive at right fielder Mike Yastrzemski. Yastrzemski made the catch and fired home; Matt Olson tagged up and burst for the plate. As Yastrzemski’s throw arrived and Olson slid home safe, a second ball entered the playing field.

From the angle of the throw, the ball appeared to be thrown by a fan from the upper deck. The throw did not interfere with the play, but the umpiring crew convened regardless. The play stood, giving Atlanta its first run of the game.

“That’s a first,” Melvin said after the Giants’ 5-4 win over the Braves. “I’ve never seen that before. I don’t know where it came from. I don’t know what the rule is. I think everybody was a little surprised by it. It didn’t affect the play, but it was extremely odd to see another baseball come onto the field.”

Hayden Birdsong, the pitcher at the time of the incident, didn’t see the throw come down from the stands.

“I thought it was the ball that was thrown home,” Birdsong said. “I was like, ‘Why is the ball way out there?’ Then I realized Patty (Bailey) had the other ball. I was like, ‘What is going on?’ I had no idea.”

Birdsong, 23, said he had never seen anything like this before.

Color commenter Mike Krukow, calling the game alongside long-time broadcast partner Duane Kuiper, echoed Birdsong and Melvin’s sentiments.

“Came out of the upper deck,” Krukow said on the television broadcast. “Some clown threw the baseball onto the field. I have never seen that.”