MESA, Ariz. -- Cubs infielder Andres Blanco will be sidelined 10 to 14 days because of a mild to moderate sprain of his right knee suffered Saturday when his foot got locked in the infield dirt at HoHoKam Park.

"It's nothing real serious," said Blanco, who was wearing a large brace on his right knee. "The doctors said I'll be fine, 100 percent in a week or two."

He injured his knee while trying to make a tag at second base in the sixth inning against the White Sox.

"As soon as I got [my foot] locked, my knee popped," he said.

Now, Blanco has to wait for the inflammation to subside before beginning treatment.

"The doctors said it won't take me too long," Blanco said.

The loss of Blanco doesn't mean shortstop sensation Starlin Castro moves up on the Cubs' depth chart. Lou Piniella said the organization plans on having Castro open the season at Triple-A Iowa because it wants the soon-to-be 20-year-old infielder to get regular playing time.

"This will give me a chance to play [Mike] Fontenot at short, which I said I needed to do," Piniella said. "We have [Darwin] Barney in camp."

Fontenot and Jeff Baker are vying for playing time at second base, but the Cubs want to see if Fontenot can be an option as a backup shortstop. That would help the team decide how to configure the bench. Barney split time between Double-A Tennessee and Iowa last season, hitting a combined .293.

"The only way Starlin would come into the equation -- and I've said this before -- is if he shows he's ready and there's a problem physically with [Ryan] Theriot," Piniella said. "I've been very impressed with Starlin. He's smooth out there, has a nice throwing arm, good hands. He gives you a nice at-bat. We'll go with Theriot at short."

Maybe Theriot could move to second base to make room for Castro?

"You guys are starting trouble already, four games into Spring Training," Piniella said to reporters while laughing. "Let's just leave it the way we said it.