Indianapolis Colts quarterback Andrew Luck is in concussion protocol, and his status for Thursday night’s contest against the Pittsburgh Steelers is "up in the air," according to the team’s website.
The Colts held a light walk-through on Monday, and Luck was not present. The only two quarterbacks there were backup Scott Tolzien and Stephen Morris, who is on the practice squad.
If Luck is unable to go, the 29-year old Tolzien would presumably get the start. He threw one pass as a member of the Packers last season, and is 0-1-1 in two career NFL starts, both of which came with Green Bay in 2013.
