"If he does well, we're looking to get him some Minor League defensive innings also," Cubs manager Rick Renteria said Sunday.
Castro is running out of time to be ready by Opening Day as the Cubs head into the final week of Cactus League games.
"We have to make sure we're careful with him," Renteria said. "He came in today and was all smiles, which is good. I'm glad he wants to play it out. We know baseball fitness is another component of the recovery process."
Castro strained his left hamstring last spring, and only missed two weeks, and was ready for the start of the season. The Cubs have played Darwin Barney and Donnie Murphy at shortstop this spring to prepare in case Castro isn't ready.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.