"It just came up in the last few days and just trying to catch it before it gets to be a nuisance for a couple months," Stewart said Friday.
X-rays were negative on Blake DeWitt's right hand. He was hit by a pitch in the Cubs' game against the Rockies on Thursday. His status also was day to day.
Darwin Barney, who has tightness on his left side, was feeling better Friday and didn't have any discomfort while coughing or laughing, Cubs manager Dale Sveum said.
The list of injured players has been minimal.
"We've been pretty lucky this spring so far," Sveum said.