To make room on the 40-man roster, the Dodgers designated for assignment outfielder Delwyn Young.
The decision to send the 23-year-old DeWitt back to the Minor Leagues is one the club has been debating since before he was named to the 25-man active roster for last week's season opener. Even then, there was concern that too much time spent on the bench in a backup role would hinder his development.
"If we envisioned a couple hundred at-bats, it would be valuable having him here," said manager Joe Torre. "At the start of the season, we don't want him sitting and not getting enough playing time."
Torre said DeWitt would play mostly second base at Albuquerque to continue learning the position. He's already adept at third base, but is not considered to have the skills to become a full-time shortstop.
"If anything happens at second base, he'd be the one," said Torre. "If something happens at shortstop, it wouldn't be him, not on an everyday basis. It would be [Chin-lung] Hu."
DeWitt started Thursday's day game in San Diego at shortstop, but has only six at-bats in three games played.
Castro, 36, is an 11-year Major League veteran better suited to the job of standing by for an emergency or making an occasional start to rest Rafael Furcal or Orlando Hudson, the middle of the Dodgers infield. It was originally assumed that Furcal would need extra days off, but he seems to be completely healthy after last year's back surgery. Hudson also is coming off significant wrist surgery, but seems healthy and in need of very little rest.
Castro, a native of Mexico, was originally signed by Dodgers scout Mike Brito in 1991, playing parts of six seasons with the Major League club, and will be returning as a Los Angeles Dodger for the first time since 1999.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.