INDIANAPOLIS (AP) The Indianapolis Colts announced Wednesday that Andrew Luck has been ruled out of Thursday night's game against Pittsburgh.
Luck has been in the league's mandated concussion protocol since Sunday night when he complained of concussion-like symptoms following a 24-17 victory over Tennessee.
Coach Chuck Pagano had remained hopeful that Luck could be cleared in time for the game, but when Luck missed practice for the third consecutive day, Indianapolis (5-5) didn't have a choice. Pagano has not said who will replace Luck, though it is likely to be backup Scott Tolzien.
Tolzien has not started an NFL game since 2013.
Indy also promoted Stephen Morris from the practice squad to the active roster. Morris has never played in an NFL game.
For more NFL coverage: http://www.pro32.ap.org and http://www.twitter.com/AP-NFL