OAKLAND, Calif. -- All-Star third baseman Josh Donaldson is the latest Oakland Athletics star traded away in a rebuilding effort.

General manager Billy Beane looked at the large deficit by which his Athletics lost the American League West to the Angels, then evaluated how Oakland barely held off Seattle on the season's final day for the second wild card.

He realized he needed to rebuild his roster once more, but at least initially he didn't envision the move he made Friday night: letting Donaldson go to the Toronto Blue Jays for third baseman Brett Lawrie, right-hander Kendall Graveman, left-hander Sean Nolin and minor league shortstop Franklin Barreto.

Donaldson told the San Francisco Chronicle that he was playing video games when his agent texted him about the trade.

"I'm so shocked," Donaldson told the newspaper. "I just got off the phone with Billy Beane, and I guess they got an offer that they couldn't resist. I'm definitely a little emotional about it. Oakland is my home. At the end of the day, it's a business, as much as it hurts emotionally. The guys in that clubhouse are my brothers."

Beane considers both pitchers ready for the majors.

"They had been pretty persistent, and we were pretty adamant that wasn't something we were willing to talk about," Beane said of dealing Donaldson. "We wouldn't have done the deal unless it addressed now and the future, and they were able to do that. This deal in our minds addresses a little bit of everything. It got pretty serious the last 48 hours. They were reluctant to give up all four players, and we weren't going to do it without those four players in the deal."

Blue Jays GM Alex Anthopoulos sweetened the deal, offering Lawrie as a replacement for Donaldson.

"I have a pretty good relationship with Billy," Anthopoulos said. "At some point, someone makes it really compelling."

At first he had been reluctant to give up four players for Donaldson, but the A's wouldn't have proceeded otherwise. Donaldson provides a steady hitter in the middle of the order for a Toronto team that finished third in the AL East at 83-79, and has watched the last-place Boston Red Sox pull off the big deals this past week by acquiring third baseman Pablo Sandoval and shortstop Hanley Ramirez.

"Donaldson's been an outstanding player," Anthopoulos said. "We're getting a middle-of-the-order bat, and it's something that we need. We didn't expect him to be available. ... It doesn't hurt to ask. We asked if there was any way we could ask about Donaldson. Billy told me emphatically no. We left it at that. A few days ago, we were talking again and asked again. Finally when Brett was involved to replace Josh, that's when it started to move again."

Donaldson's Value According to wins above replacement, only Mike Trout has been more valuable than Josh Donaldson among position players the past two seasons:

Most Wins Above Replacement Mike Trout 16.7 Josh Donaldson 15.4 Andrew McCutchen 14.4 Robinson Cano 13.9 -- ESPN Stats & Information

Donaldson, 28, a sure-handed, athletic defender, batted .255 with 29 home runs and 98 RBIs in 158 games this past season, and was named to his first All-Star team. In four seasons in the majors, all with Oakland, he has a .268 average with 63 home runs and 228 RBIs in 405 games.

In his only two years as a regular, he finished fourth (2013) and eighth (2014) in AL MVP voting.

Anthopoulos can't wait to see Donaldson's bat alongside sluggers Jose Bautista and Edwin Encarnacion.

"You are going to have to give up some really good players to get Donaldson," Anthopoulos said.

Oakland, which won the AL West in 2012 and '13, lost by 10 games this past season to the big-spending Angels. The A's then were eliminated 9-8 in 12 innings in the wild-card game at eventual AL champion Kansas City.

Beane wasn't sure Oakland could contend for the division again without some key additions, especially after losing left-hander Jon Lester following his short stint since being traded from Boston at the All-Star break.

"When we went into this winter, we had to take a look where we are and where we're headed," Beane said.

A's left fielder Josh Reddick told the Chronicle it is apparent the team is in a rebuilding phase.

"This doesn't make sense to me. We just traded our best player the last two years," he told the newspaper.

Josh Donaldson belted 29 home runs to go with 98 RBIs this past season for the A's. Thearon W. Henderson/Getty Images

Beane already has been plenty busy.

On Nov. 19, he signed designated hitter and former Royals star Billy Butler to a $30 million, three-year contract. Just this past Sunday, the A's acquired first baseman Ike Davis and international bonus slot 86 from the Pittsburgh Pirates in exchange for international bonus slot 27.

Lawrie batted .247 with 12 home runs and 38 RBIs in 70 games for Toronto this past season. He missed most of the final three months because of a broken finger and an oblique strain.

Graveman recorded a 3.86 ERA in 4 2/3 innings pitched over five major league games this past season.

Nolin is expected to compete for a rotation spot, despite only 2 1/3 innings pitched with a 27.00 ERA in the majors.

Barreto, 18, is a .296 hitter in 132 minor league games. He is "exciting, but a ways away," a scout told ESPN.com's Jerry Crasnick.

"We addressed a lot of areas we thought we needed filled from our organizational standpoint," Beane said.

The A's still are in need of a shortstop with Jed Lowrie a free agent. Finding that player also might come through a trade because "I certainly won't see it through free agency," Beane said.

The Athletics also are open to trading Jeff Samardzija in "the right deal," a source told Crasnick.

To clear spots on the 40-man roster, the A's designated right-hander Josh Lindblom and first baseman Kyle Blanks for assignment.

The Associated Press contributed to this report.