Ray Edwards is the obvious choice because it's the first time all pre-season he's taken the field. That's not the only reason, though.
Edwards will be worth watching because he's the off-season's biggest addition, aside from blockbuster rookie Julio Jones. He'll be worth watching because he's the clear starter opposite John Abraham, and he's at the very least a capable pass rusher. It won't melt your face off, but 29.5 sacks in five seasons is pretty good.
It's worth noting that 16.5 of those have come in the last two seasons, suggesting the 26-year-old end is coming into his own. For those that think Edwards can't be effective without an elite defensive end bookending him...well, I won't argue. I'll just note that the Falcons currently have John Abraham, so it's hard to argue he doesn't have any help.
So on those merits alone, I'm going to keep my baleful eye fixed on Edwards. But there's also the fact that the Steelers offensive line offers an quality challenge, that Ben Roethlisberger isn't easy to bring down and that Edwards is probably only getting a half-game tune-up. I'll be looking to see how much intensity he brings, whether he looks fully healthy and if he can drop Big Ben a time or two.
Who's your player to watch?