The Colts are listing quarterback Peyton Manning as 'doubtful' for Sunday's Week One opener against the Houston Texans. As Aaron Schatz correctly pointed out, since 2003 no Colts player listed as 'doubtful' has ever played on Sunday.
There is currently no timetable for Peyton's recovery.
From the Colts official release:
During the last week, the rate of improvement in Peyton’s rehabilitation process slowed. Over the weekend Peyton experienced soreness in his back. It was originally thought to be a normal reaction to his rehabilitation regimen. When the soreness persisted, the Colts medical team decided to initiate diagnostic tests and to consult with a number of specialists around the country who have been involved in Peyton’s case from the outset. That process continues. As a result of the most recent development the doctors have decided that Peyton will not practice. His participation therefore, in Sunday’s game versus Houston will likely be doubtful. We will update his playing status as required by NFL policy as the week goes on.
We're waiting for the Colts press conference to discuss Manning's health and status for 2011. For now, consider Manning OUT for Week One. Kerry Collins is expected to start, and the longest active streak for games played by a QB will likely end this Sunday.