SAN FRANCISCO -- Padres manager Bud Black could have some more weapons at his disposal on Wednesday for the series finale in San Francisco.

Second baseman Jedd Gyorko is expected to return from the paternity list after his wife, Karley, gave birth to twin boys on Monday. Gyorko, who was away Monday and Tuesday, is eligible to miss up to three games, but Black will surely be eager to add him back to the fold, even if he is struggling with the bat.

Meanwhile, outfielder Seth Smith is recovering well from a right groin strain he suffered on Thursday in Washington. Smith was out of the starting lineup for the fifth straight game, but took batting practice again on Tuesday and was available to be used as a substitute.

If all goes well, Smith could be inserted back as the starting left fielder by Wednesday.

"That's not out of the question," Black said before Tuesday's matchup. "All that depends on how he does today in the pregame when he ramps up the intensity of his running out here. I'll have a better idea once this game unfolds, how he feels."

Peterson enjoying first taste of big leagues

SD@WSH: Peterson gets first hit while parents watch

SAN FRANCISCO -- Just eight months ago, Jace Peterson was with Class A Advanced Lake Elsinore. Just eight days ago, he was still with Double-A San Antonio.

Clearly, it's been a wild ride for the infielder as he's climbed up the organizational depth chart, earning his first big league invite when Padres third baseman Chase Headley went down with a right calf strain on Thursday. For the third time in four days, manager Bud Black penciled in Peterson as the starting third baseman on Tuesday against the Giants.

Peterson slapped a single up the middle against Stephen Strasburg on the first big league pitch he saw during his debut on Friday in Washington. On Monday, he recorded the first two-hit game of his career, going 2-for-4 with a stolen base.

"It's awesome," Peterson said. "Any time you can get your debut and also do something to help the team, it makes you feel better. At the end of the day, you want to win, and that's the most important thing."

Peterson has established himself as a spark plug throughout his Minor League career, as he batted .303/.382/.454 with seven homers, 66 RBIs and 42 stolen bases in 2013. Though he has spent most of his time at shortstop while in the Padres' system, the 23-year-old has shown nice athleticism while at third base in Headley's absence.

"Jace has done a nice job," Black said. "Made a couple nice plays yesterday, made a couple nice plays in Washington. Jace plays at a pace that lends itself to good baseball. He's competitive, but yet plays with an in-game awareness. For a young player, that's good to see."

Grandal gets first big league start at first base

SD@WSH: Grandal doubles in a pair to take the lead

SAN FRANCISCO -- Tuesday night might have marked catcher Yasmani Grandal's first Major League start at first base, but the Padres' regular catcher is very familiar with that patch of the infield.

While many of his teammates like to shag fly balls in the outfield during batting practice, that's too boring for Grandal. For as long as he can remember, Grandal has trotted out to first base during the pregame sessions.

"I'm always catching ground balls at first, and it's not because I want to show off that I can play it," Grandal said. "It's just because I like to keep my legs loose. I don't like just standing there in the outfield. ... That's the routine I've always done."

Once he got to the clubhouse Tuesday, manager Bud Black asked Grandal if he would feel comfortable playing at first base, where he last appeared during a wild 17-inning affair on May 31 against the Blue Jays. He went through the 2013 season knowing he was something of an emergency first baseman for the Padres, so he wasn't completely caught off guard.

"I told him I'm comfortable playing there," Grandal said. "Worst thing that could happen to me is they could hit a hard ground ball to me, and if I feel like I'm going to miss it, I'm going to block it. I'm going to let it hit my chest and get the other guy out. ... It's definitely going to be fun. Something new."

Nick Hundley was behind the plate Tuesday after fellow backup Rene Rivera erupted for five RBIs in Monday's 6-4 win over the Giants. Meanwhile, first baseman Yonder Alonso was on the bench for the second straight game, as he's mired in a 4-for-40 (.100) slump since April 16.

Black didn't sound like he had many reservations about giving Grandal the start at a position he hasn't played since he was a Minor Leaguer in 2011.

"Better than 2010," Black said. "We wanted to get his bat in the lineup and Nick's bat in the lineup. ... [Alonso] will be back in there at some point. We need Yonder, no doubt about it. It's an offensive position, first base."

Worth noting

Tyson Ross hosted a team of Little Leaguers and their families from nearby San Leandro for Tuesday's game. Ross, a Bay Area native, sponsored the team with camouflage Padres jerseys for the season and spent part of the pregame session mingling with the players and coaches.