It seems like the biggest story in sports this week is about a joint. Thankfully, though, it's not one that a player got caught smoking. It's one that is in bad shape. San Diego Chargers' linebacker Shawne Merriman has damaged two ligaments in his knee. Four different doctors have advised him to have surgery to repair the knee, yet Merriman has chosen to ignore that advice and going ahead and play. It seems like he could be risking serious, and potentially career ending, injury, yet Merriman downplays that, and is adamant that he just wants to play. The debate has raged throughout the media all week. As I see it, there are really only three issues involved:

1. The decision - I'm really tired of everyone throwing their opinions around and damning Merriman for his decision. Don't think it seems like the right decision, but that doesn't matter at all. I've never been a world-class linebacker, I don't know how his knee feels, I've never had a massive contract on the horizon, and I don't know exactly what the doctors said, so at the very least my opinion is based on incomplete information. I can say that I would have made a different decision, but I don't know what went into the decision, so it's a ridiculous comment. Further, the Chargers have a valuable asset in Merriman, and they wouldn't risk that it if it didn't make sense, regardless of what Merriman wants. This whole story has been overblown in this regard.

2. What this means for opponents. The game has changed significantly for offenses playing against Merriman. The linebacker was the kind of player you avoided at all costs. He was ferocious against the run, and a deadly pass rusher, so teams would either be forced to double team him or run plays away from him. Now he is vulnerable, and that changes everything. Merriman now has a weakness, and teams will look to exploit that weakness at every opportunity. They'll go for his knee whenever they can, and they'll force him to make the lateral moves that will test his knees whenever possible. There are two things there - by going for the knee they may be able to knock him out of action, and even if they don't they should be able to make Merriman hesitate or second-guess. If they can get Merriman to hesitate for even a split second, or if they can slow him down even half a step then he won't be nearly as effective as he is. That means that opponents can run a more varied offense than they otherwise might, and might find more success against the Chargers than they otherwise would. It's no exaggeration to say that this is extremely good news for teams that have to face the Chargers. San Diego is still an elite team obviously, but this is a chink in their armor, and that can give an opponent strength.

3. What this means for the Chargers. San Diego will have assessed this decision and made sure it's the best thing for them. As long as they are reasonably comfortable that Merriman isn't going to do massive damage to the team, they did some basic math - Merriman at even half strength is better than almost every other linebacker in the league at their best. That sounds silly, but Merriman is that good. He's also a big leader on the defense, and whether you agree with what he is doing or not, you can't deny that it will fire up his teammates and make him an even better leader. If Merriman stays healthy, or close to as healthy as he is, anyway, then the Chargers will be happy.

That, of course, is a big if. Opposing defenses are going to be hunting Merriman's knee, and it seems unlikely from this perspective that he will make it all the way through the season unscathed. If he doesn't then San Diego faces two challenges - replacing the player and protecting the psyche of the team. Neither will be that easy, but it seems worth the risk for one big reason - this is a really deep, talented team. The impact of a loss would be bigger if Merriman was the only star on the team, but since he isn't even the biggest star who wears a thunderbolt the team should be able to survive whatever happens. They will of course be impacted, but not fatally. When you look at it that way this decision isn't quite as stupid as it may first seem.