Stephania Bell an orthopedic specialist and an injury expert for ESPN. She can he heard talkin' about the various maladies suffered by pro athletes on several ESPN podcasts and occasionally appears on TV. Bell has been keeping a close eye on Peyton Manning's recovery from "fusion surgery" since long before he left the Colts.

Yesterday she published a lengthy article on the topic for ESPN.com. She saw his participation in the Broncos' first pre-season game as significant, saying: "There is no longer any doubt that Manning will indeed line up under center for the Broncos this season".

Manning had his sixth vertebrae fused to his seventh with a steel plate. The surgery went as well as it could have been expected to go, and Manning's doc cleared him to play last December: "On Dec. 1 after a post-operative re-evaluation, Watkins stated the fusion had achieved "firm fixation." In other words, the two vertebrae that were fused together with the aid of a bone graft showed evidence of healing. At that time, Manning was cleared to begin throwing and to increase the vigor of his rehabilitation"

Bell notes that surgeries like the one Manning had can extend the careers of athletes afflicted with neck injuries and points out that: "The argument could be made that Manning is no more at risk from a substantial injury as a result of a direct hit than any other NFL quarterback who steps onto the field".

As for the progress of Manning's rehab, the primary concern is no longer his neck - it's the strength of his right arm. Having sat out an entire season and having not been able to throw for several months, Manning's muscles naturally degraded and a damaged nerve between his vertebrae took longer than expected to heal. His throwing strength still isn't quite what it once was and nobody knows for sure whether or not it ever will be.

Bell is optimistic, although, she's reserving judgement until Manning has played the entire 2012 season: "It will be only in retrospect once the season is complete that Manning will have proven whether he could, in fact, endure another season in the NFL and his performance will indicate whether or not he was able to live up to expectations"