"Sports editor Al Saracevic did a fine job outlining the potential pratfalls and positives of the 49ers signing Colts quarterback Peyton Manning. After perusing the pro and con and adding a few more cons, it's clear that signing a 36-year-old with a severe neck injury to a team that doesn't pass protect well is a bad idea and here are the reasons why.

1. BAD ASSUMPTION: In assessing Manning-as-Niner perspectives, the assumption is Manning will pick up right where he left off in 2010 as an intelligent sharp shooter capable of throwing 30 touchdown passes a year. But can we automatically assume Manning will have the same strength as before, and at 36, he will likely be more immobile than ever, and there's a decent chance he and his fused vertebrae won't even survive the preseason.

2. BAD ASSUMPTION II: Manning built his Hall of Fame numbers all in the same offense. Now can this old dog learn a new offense? He probably can but how long will it take? And will Manning want to pour in the extra hours to learn it as an NFL senior citizen. Saracevic also points Manning has been so used to doing offense a certain way, isn't he likely to challenge the concepts of NFL coaching greenhorns Jim Harbaugh and Greg Roman? Manning can't expect to be the audible-mad quarterback he was in Indy, at least not initially. "