Belt's inclusion on the roster set off a ripple effect of moves. First baseman Travis Ishikawa was designated for assignment, and Aubrey Huff, who spent much of last season at first base, officially became the team's starting right fielder. Cody Ross, who was slated to start in right, will begin the season on the disabled list with an injured right calf.
"I'm going to be tearing up the rest of the year in right field with my legs," Huff joked, as reporters surrounded Belt.
Huff was one of a long line of veterans who dropped by Belt's locker to shake his hand and congratulate him on making the team.
"He's done everything right in spring," Huff said. "He's a great guy. ... He's a real quiet, humble kid. A lot of inner confidence."
As for the pitching staff, Ryan Vogelson and Steve Edelfsen were also sent down. The final two bullpen jobs went to Guillermo Mota and Dan Runzler.
"Both of them have been throwing well and they both threw well last year, and they've earned a spot on this club," Bochy said. "I really like where Runzler is now. He's commanding the ball very well, and Mota's had a good spring."
Belt, a fifth-round pick in the 2009 First-Year Player Draft out of the University of Texas, had a meteoric rise to the big leagues. He hit a combined .352 with 112 RBIs and 23 homers last year with stops at Class A San Jose, Double-A Richmond and Triple-A Fresno. He hit .282 with three homers and 13 RBIs this spring.
He'll make his big league debut against Dodgers left-hander Clayton Kershaw, a player he faced in high school in Lufkin, Texas.
"This is an unbelievable feeling right now," Belt said. "Almost doesn't seem real. I've got a lot of emotions right now I'm trying to contain.
"I've been thinking about it, pretty much my entire life, and it all came to a head today. Like I said, it's just surreal. I don't know what's going on right now. I'm just trying to process this whole thing. Hopefully it will go well."
Bochy hinted on Tuesday that Belt might make the team, but he said the news seemed to stun the rookie on Wednesday.
"When you have a guy like Belt and you're able to give him great news, and see what it meant to him, it's special," Bochy said. "He was a little floored, I think, very excited, but also a little overwhelmed with the fact that he's in the big leagues. It's your dream, and he's very, very excited about this. But he's earned this. He makes us a better club with what happened with Ross. We wanted to break with the best club, and right now we feel having Brandon on the club makes us that."
Ishikawa has been with the Giants organization for his entire career, which began in 2002, but the first baseman has never been able to hold onto the starting job. Last year he was primarily a pinch-hitter and defensive replacement. As a pinch-hitter, he went 15-for-47 (.319), the seventh-highest clip in the National League.
"I planned on making the trip, so I packed" for Los Angeles, Ishikawa said. "I've been saying all spring it's a business, it's part of the game. I've been around here long enough, you can see. You kind of anticipate these things. Definitely it's tough to chew when it actually happens.
"The last week or so I thought I was on the team. Today showed that it is a business. I understand that the Giants are trying to move forward and get back to repeating as world champions. I'll definitely take these last nine or 10 years to heart. These guys brought me into the system, brought me up. I'll always be grateful to them for that. I wish them the best of luck. I don't know where I'll be, but if I'm not playing I'll be rooting for them for sure."
Ishikawa may not know his fate for 10 days. The Giants could trade, release or waive him. If he clears waivers, they could send him to Triple-A Fresno, but Ishikawa would have the right to refuse the move and become a free agent.
In another move, veteran reliever Marc Kroon was sent to Triple-A Fresno. Kroon said he's not sure if he'll report, but Bochy is lobbying hard. He went 2-0 with a 1.69 ERA and 13 strikeouts in 10 2/3 innings this spring.
"I really hope he stays," Bochy said. "I love this guy. ... He comes in Spring Training and does just a terrific job. He pitched well enough to be on a Major League team. The numbers probably caught up with him."
Catcher Chris Stewart and infielder Ryan Rohlinger were also sent to Fresno.