Mitch Atkins was optioned to Triple-A Iowa and David Patton, whom the Cubs acquired in December 2008 in the Rule 5 Draft, was optioned to Double-A Tennessee. Both are right-handed pitchers.
Jackson, Vitters, catchers Steve Clevenger and Blake Lalli, infielder Matt Camp, and pitchers Jeff Kennard and Vince Perkins all were assigned to the Minor League camp.
"It was a good experience for all these kids, and hopefully, they'll be back here sometime," Cubs manager Lou Piniella said.
Jackson, an outfielder, was the Cubs' No. 1 Draft pick last June, while Vitters was the top pick in 2007. Vitters, who was bothered last season by a wrist injury, hit .316 at Class A Peoria and .238 at Class A Daytona.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.