CHICAGO -- Chicago Cubs reliever Blake Parker, just called up on Thursday, was pulled from his second career outing Saturday with an right hamstring injury.

Parker was pitching to the White Sox’s Alejandro De Aza in the eighth inning when he winced in pain after firing a pitch.

Afterward, Parker said he felt something akin to a cramp one pitch before he was removed. He tried another pitch and the pain was more intense.

The injury isn't expected to be serious. He will be re-evaluated Sunday morning.

The Cubs already have Lendy Castillo, Steve Clevenger, Carlos Marmol, Geovany Soto on the disabled list.