For the first time in his five-year career with Cincinnati, Andy Dalton will likely be watching, and not playing, on Wild Card Weekend.
Lewis declined to offer an update on Dalton's fractured thumb.
He did, however, tell The MMQB's Peter King on Saturday that Dalton remains "very optimistic" even if the team's doctors aren't quite as gung-ho about pushing the thumb.
"I feel he's got an opportunity to play next weekend," Lewis said, "but we're going to err on the side of caution."
Dalton is scheduled to see a hand specialist on Monday. If all goes according to plan, he will have his cast removed to begin the process of regaining range of motion in his throwing hand.
McCarron has exceeded expectations as a caretaker for the Cincy offense, but has averaged just 28 pass attempts per game. Sunday's win against the Ravens was the team's first without converting a single third down since the 1995 season opener, per Hobson.
McCarron will have to show marked improvement to avoid a repeat of the Week 14 loss to the Steelers in which he replaced an injured Dalton in the first quarter.