Joe Burrow: Cincinnati Bengals' key player, crucial for Super Bowl aspirations.
Burrow: Calf injury at Bengals practice, carted off field.
Team uncertain about injury severity and return timetable.
Coach Zac Taylor confirms strained calf and soreness.
Teammate Ja'Marr Chase expresses confidence in Burrow's recovery.
Burrow seen wearing sleeve on injured leg, unusual for him.
He led Bengals to consecutive AFC Championship game appearances.
Burrow tops NFL in passer rating (104.8) and ranks third in touchdown passes (69).
Burrow's absence poses challenges for Bengals' Super Bowl journey.