After suffering a setback this weekend in his rehabilitation from neck surgery, the Indianapolis Colts' Peyton Manning will "likely be doubtful" to play this Sunday, according to a team statement released today. Manning, who has started every game for the Colts since entering the NFL in 1998, was recently removed from the Physically Unable to Perform list, the first step toward a return to practice after neck surgery in May. However he reported soreness in his neck over the weekend, and team doctors have said he won't practice this week, putting his readiness to start the regular season this coming Sunday in serious doubt. [via NFL.com]