After reading all the comments, it seems that it would be helpful to refresh memories. I will only briefly summarize the pertinent points (specific to Demeco) of the analysis of NFL players that I reviewed previously for Stephanie's blog in the Chronicle.
*1/3 of the players were NEVER able to return to the NFL
*Defensively, linebackers experienced the greatest drop in power ratings (DEFENSIVE POWER RATING calculated as a total of TACKLES + INTERCEPTIONS), followed by cornerbacks, defensive tackles, and defensive ends. The average decrease was 95% (p=0.09), 87% (p=0.03), 64% (p=0.01), and 55% (p=0.03), respectively. In other words, LBs were the players (both offensive and defensive) that had the most drop off of all players to return.
*Their 1st season post injury tended to be their BEST performing season post injury.......but significantly down from the 3 years prior to injury. Each subsequent post injury season saw a DECREASE (not an increase)in performance from the prior season as measured up to 3 years post injury.
As I explained at the time that I presented the data, there were definite limitations to the study. But even if you felt justified in halving the post injury power rating losses due to these limitations, the numbers would still be quite discouraging.
According to the available data, absent Demeco's elbow injury, this season could have been Demeco's best chance to show his most productive post injury season. There is always that "miraculous" exceptional case that occurs out there, and that is true.......but realistically the odds are not with Demeco.