Actually, this is a huge and ground-breaking addition to the game...you're downplaying the significance. Either that, or you just didn't bother to read the whole article.
To take the example in the article a little further, let's say that you're the Indianapolis Colts, it's week 17, and a playoff spot is on the line. You're trailing 34-28 with less than two minutes remaining, and Peyton Manning goes down with a shoulder injury. Do you keep Manning in and risk further injury to the man that will undoubtedly be key in a playoff run, or do you go with backup Jim Sorgi for your last ditch game-winning drive, who is admittedly quite a downgrade at QB?
Really, what elevates this feature from cool to amazing is the fact that it ties in perfectly with the new rating system, and the noticeable difference in talent. From other blogs I've read, you'll most definitely be able to notice the difference between a Manning and a Sorgi, so in the example I used, that decision is huge. The level of roster strategy is also elevated to a new level. You'll have to spend money on quality back-ups in order to survive if a player is injured...and if you don't, the consequences could be dire.