Sogard, catcher Josh Donaldson and right-hander Tyson Ross were sent to Triple-A Sacramento. LaRoche, catcher Landon Powell and left-hander Bobby Cramer survived, grabbing the final three available roster spots.
Sogard had the edge defensively, but LaRoche, a right-handed hitter, had a huge advantage offensively during the spring. He hit .333 with 13 RBIs and four home runs -- both team highs -- to Sogard's .209 average, four RBIs and zero homers.
"Each one of them had strengths over the other one in certain areas, or weaknesses over certain areas," A's manager Bob Geren said. "One's a right-handed hitter, one's a left-handed hitter, one's a contact kind of guy, one's more a power hitter. There were a lot of variables involved to try and make that decision. We felt like Andy could do it. He's had some big league experience. We're going to go with him. He played well. He had a good spring."
To clear a spot on the 40-man roster for LaRoche, the A's placed infielder Adam Rosales on the 60-day disabled list retroactive to March 22. He is still recovering from a fractured right foot and offseason surgery.
Sogard took his demotion in stride.
"I knew it was going to be a close call," he said. "It was a coin flip. That's what they said, between me and LaRoche there. I came to Spring Training and did what I wanted to do, proved to them I can play defense, shortstop, second base. Still working on the third-base position, but I'm happy with the spring. I didn't hit as well as I can, but my main focus was defense, and I did what I wanted to do there.
"I'm happy to have this opportunity. I think it's a good thing for me. I'll be able to get down in Triple-A and play every day and get back in the swing of things. I think I'm more of an everyday player. The way I compete every day helps me out more than playing once every week, so that'll be nice."
As expected, the A's also placed closer Andrew Bailey (strained right forearm) and right-hander Rich Harden (strained right shoulder) on the 15-day disabled list.
In other moves, infielder Wes Timmons and outfielder Matt Carson, two non-roster invitees, were sent to the team's Minor League camp.
Cramer and Ross competed for the fifth-starter's role that went to Brandon McCarthy. Ross went 1-0 in the spring with a 0.59 ERA, while Cramer went 0-2 with a 7.16 ERA.
Geren, though, made it clear that he was impressed by Ross' spring performance and wants him to continue getting work.
"He's their best young Minor League pitcher without a doubt," the manager said, referring to the A's organization, "and he's going to go down there and pitch well, and he's going to create a spot here one way or another, through competition or any injury, any bumps or bruises. Ideally, he goes down there and starts off the way he pitched in the spring and just creates a spot. He has that type of ability."
"He had a couple, three good outings for us last year," Geren said. "You look at that. He pitched pretty well this spring. He had one rough outing against the White sox, but other than that he threw pretty well. He'll be able to be a long guy, middle guy, pitch in different situations with a little flexibility."
Cramer made an Opening Day roster for the first time in his career.
"My biggest goal coming into camp was to make the team, and I made it," said Cramer. "I always believe in myself and thought I could get up here and stick, and this is the start of that. I'm going to do everything I can to stay up here and not get sent back down and help the team and try to make a career out of it."
Eric Gilmore is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.