Petrick was optioned to Triple-A Iowa. The others were non-roster invitees, and they were assigned to the Minor League camp. The list includes right-handed pitchers Esmailin Caridad and Jose Ceda, left-hander Geoff Jones, outfielders Colvin and Andres Torres, infielder Bobby Scales, and catchers Wellington Castillo and Josh Donaldson.
Petrick had been up in the Major Leagues last season and appeared in eight games, but was sidelined at the end of the year with shoulder soreness.
"Coming off his injuries, we would be remiss to try to force him to get ready by the 28th, 29th of the month," Cubs general manager Jim Hendry said. "We feel he's a long-term player for us. We feel if we rush him and he goes out there and he's not ready to go two or three days in a row, and he tries to force it, it would not be a good situation for him.
"We all know when he's right and he's healthy, he's good enough to pitch for us," Hendry said. "He couldn't get ready by the end of the month."
Ceda, who spent most of last season at Class A Peoria, needs to get command of his fastball better and develop a second pitch, Hendry said.
"Every year you go to camp and say, 'It's going to be hard cutting this thing down,'" Cubs manager Lou Piniella said, "but as it goes on and goes on and goes on, it becomes easier because the players make the decisions for you.
"It's a great experience for them [to be in big league camp]. When they get back here, they've had a taste of it."
With the moves, the Cubs' spring roster now is 50, and consists of 26 pitchers, four catchers, 12 infielders and eight outfielders.
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.