"For a rookie, the key is to think more, but not too much. To pay more attention to your surroundings, to everything happening here and there and everywhere, but not too much. To keep your head on a swivel, but not too much. Otherwise, it's just too much. %u201CA year ago, my entire focus was on competing for the spot and making this team, and I don't think I really realized what there was around me until I actually did,%u201D said Chargers receiver Legedu Naanee. %u201CIt was only after the season started that it hit me: Man, we're stacked.%u201D Even with so many of the game's most celebrated weapons, the Chargers offense eventually became even more stacked with the additions of Naanee and Buster Davis, two rookies who surely could've picked an easier place to break into the National Football League. At the same time, their neophyte status also could be cited as a reason things got turned around in the middle of last season. Partially because the two rookies weren't ready, the Chargers made the mid-October trade for veteran wide receiver Chris Chambers, a much-needed turning point in San Diego's fortunes after a dreadful start. %u201CThat was a good decision upstairs,%u201D Davis said yesterday. %u201CIt gave me the opportunity to look back and time to learn.%u201D So here they are, rookies no more. To be sure, they're wise enough to be the only returnees from the Chargers receiving corps taking part in these first few days of training camp, getting a head start on making a second first impression. %u201CThe first thing is that they now realize how competitive this league is and how hard it is to make a play,%u201D said head coach Norv Turner. %u201CThey've been through it. They have a much better understanding of what we're asking them to do. And they both have established a good rapport with Philip.%u201D Philip Rivers, of course, is the guy who distributes the football to what he calls %u201Carguably the deepest, best receiving group in the league.%u201D Because the Chargers are so solid and such a target-rich environment as camp opens %u2013 the full squad reports tonight %u2013 there's a very real possibility that Davis and Naanee again will be the newest guys in the bunch in terms of NFL service time. %u201CI see a huge difference in both of them this year,%u201D said Rivers. %u201CBoth those guys are easy to build a relationship with, both as a friend and on the field, and it's been a smooth transition from their first year to the second. Any player who's been through the development process at any position, though, will tell you it takes time. %u201CYou can already tell that everybody's comfort level has been raised. They have a better understanding of the system, for one thing, and what's asked of them, for another. When a player first comes in, they get moved around and you wonder what are we going to do with him. Now we know what they bring, so the roles they play get more specific.%u201D Another difference is that in Chambers and