Smith was limping noticeably Monday and wearing a protective boot because of a high ankle sprain. Smith's agent, Derrick Fox, said the four-time Pro Bowl pick "most likely" will sit out Sunday's game against Chicago.
Smith repeated coach John Fox's line of being "day to day," but also acknowledged his slight chances of a speedy recovery. The Panthers have a bye a week after facing the Bears.
"I'm not a doctor, but if I can't walk without a boot," Smith said, without finishing the sentence.
Smith hurt his left ankle in the third quarter of Sunday's 16-14 loss at New Orleans when a defender fell on his leg after he made a catch along the sideline. Smith hobbled off the field, then was carted inside for X-rays, which were negative.
Smith said he wasn't feeling much better on Monday.
"Just trying to walk," he said.
Smith's absence further depletes Carolina's struggling offense, which ranks last in the NFL at 11½ points a game. Smith, Carolina's only experienced receiver, has 13 catches for 174 yards and two touchdowns.
It's likely the Panthers will start two rookies, David Gettis and Brandon LaFell, at receiver against the Bears. Carolina (0-4) already starts rookie quarterback Jimmy Clausen.
"It's time for us to step up," Gettis said. "We have to."