"There's a lot of Major Leagues that are going to be playing in it on other teams, so I'm really looking forward to playing in the WBC," Aoki said.
Veteran reliever Luke Gregerson jumped at the chance to represent the U.S. He will make the short drive to Miami on March 6 for workouts. He said he would have had to "been broken in half" to turn down the chance to play in the World Baseball Classic.
"It's an honor," he said. "I got a phone call asking if I was interested in playing again. It was a text message [from Joe Torre] initially. I said, 'C'mon, is this is a serious question? Absolutely. I would love to.' It's a tremendous honor to be able to play for your country, and wearing that Team USA across your chest is pretty exciting."
Bregman will join Gregerson on Team USA's roster and will also leave camp on March 6.
"I'm super excited," Bregman said. "It's going to be a blast. It's an honor to represent Team USA. Just have to get ready a little bit sooner, get ready to play nine innings a little bit sooner. I knew that going into this offseason, so I'll be ready."
Other Astros scheduled to play in the World Baseball Class are All-Star second baseman Jose Altuve (Venezuela), designated hitter/outfielder Carlos Beltran (Puerto Rico), shortstop Carlos Correa (Puerto Rico), pitcher Kevin Chapman (Canada) and pitcher Dayan Diaz (Colombia), who's a non-roster invitee to camp. Chapman's father is from Canada.
Manager A.J. Hinch said Diaz, who was signed late in the offseason, could be delayed coming to camp by one or two days as he works through his travel arrangements.
Brian McTaggart has covered the Astros since 2004, and for MLB.com since 2009. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.