MIAMI -- Rookie infielder Travis Denker always looks at the lineup card before a game.

But Sunday was a little bit different.

After a rainout on Saturday forced a doubleheader on the final day of the Giants' series with the Marlins, Denker walked into the clubhouse and found his name on a Major League lineup card for the first time.

"I kind of did a double take," Denker said. "I'm on the team, though, you know?"

Denker, 22, already made a little bit of history before his first Major League at-bat. On Aug. 26, Denker was part of the first trade between the Dodgers and Giants in 22 years when he was the "player to be named later" in a deal that sent Mark Sweeney to Los Angeles on Aug. 9.

"He needs the start up here. You can't sit him too long," Giants manager Bruce Bochy said. "They've got a left-hander going [in Mark Hendrickson], and that's why he's here in the first place."

Denker was called up from Triple-A Fresno following Tuesday's game against the Rockies. The 5-foot-9 right-handed hitter made his Major League debut on Wednesday in Colorado and flied out as a pinch-hitter against Matt Herges.

Denker played second base -- he can also play third -- and hit in the No. 7 spot, knocking his first Major League hit in the fourth with a double off Hendrickson.

Denker never played above Class A prior to the 2008 season. The Fountain Valley, Calif., native hit a combined .277 with 66 home runs and 288 RBIs in six years and 524 games in the Minor Leagues.

"He's a good hitter that's aggressive. He'll give you some good swings, and he's got a small strike zone," Bochy said. "Defensively, he's gotten better and better."

But Bochy can't be sure about his assessment on the young infielder, because he hasn't seen much out of him. His teammates feel the same way.

"He's only been up here a few days, so I don't know much about him," veteran outfielder Randy Winn said. "He'll get his feet wet [on Sunday], and hopefully after today, we'll find out a lot more about him."

Even Denker doesn't know what to expect.

"I guess I'm a little anxious, more than anything," Denker said. "That's what I try to tell myself. I'm a little bit nervous, but I feel good. I just try to relax.

"But I have no idea what it's going to be like."