The Carolina Panthers had a sigh of relief on Sunday after watching Cam Newton walk without a boot on his left foot.

Newton suffered a mid-foot sprain in Thursday night's preseason matchup against the New England Patriots. He was immediately ruled out of the game, and left the stadium with the boot on his left foot.

Ron Rivera said that there's no timetable on his return, but they are 'cautiously optimistic' that Newton will be ready for the season opener against the Los Angeles Rams.

Newton was nursing a shoulder injury heading into the season also -- so he'll have to remain extra cautious.