PHILADELPHIA -- The practice squad wide receiver is taking reps with the first team. The second-round pick is not. The veteran safety is working largely with the second team. What does it all mean?

Not much, probably.

In a few days, we will start worrying about starting units that look flat and listless in the opening preseason games. The offense cannot sustain drives. The defense generates minimal pass rush. Cancel the season tickets? Speed-dial the sportstalk station, foaming at the mouth?

Hold your horses. 

The first "unofficial" depth charts of training camp have been released to the media. Matt Cassel is a starter in Minnesota, Teddy Bridgewater a backup. Andre Holmes, a practice-squad Bonus Miles Reward member who made a handful of starts last year, is listed at wide receiver ahead of free-agent James Jones. The Falcons forestalled controversy about their 4-3/3-4 system by releasing a nickel depth chart. What gives?

Nothing gives. The depth charts mean little. Same with the "first team reps." Preseason performances are misleading, even in the first quarter. Coaches don't care about what we care about. 

We claim to be too NFL savvy to place too much stock in camp depth charts and preseason results. Yet we cannot help ourselves. Depth charts are tangible, practice reps visible. They are concrete things to talk and write about. Rookie C.J. Mosley is listed as a starting linebacker in Baltimore. Rookie running back Charles Sims is behind both Doug Martin and Bobby Rainey in Tampa Bay. Discuss it. Blog about it. Even if it means precious little.

Coaches are usually candid about just how fluid depth charts are in early August, and how nonexistent preseason game-planning is. But coaches are rarely as specific as Eagles defensive coordinator Bill Davis was when he discussed his philosophy of preseason football on Monday. 

"The goal of the preseason games is to get great evaluation of your players," Davis said.

Sounds simple and obvious. So why all of the obsession about which players take reps with which team? For Davis and other coaches, it's a lot of misguided speculation. "Sometimes, we get veterans out early so we can see if the two's can handle their one's," he said. "It makes a little chaos in training camp, but it's good chaos. We're doing it for a specific reason: our evaluation of a two on a one, or a three on a one."

Davis said the same things coaches around the league have been saying for two weeks. He just said them more clearly and explicitly than most coaches, who hate press conferences like prostate exams and grow paranoid about sharing even common-sense nuggets of real information with the public. August is the only time of year when teams can spare the time to make young players comfortable working with veterans and evaluate newcomers about their mastery of the basics. Ironclad depth charts and clever game plans would actually get in the way.

For Davis, training camp is the time to shuffle player combinations, allowing new teammates to adjust to one another. "If you leave the one's with the one's, communication gets smooth," Davis said. "But then some backup comes in, and communication gets different. So we need to get everybody within a comfort zone."

The constant loud music and fast tempo of Eagles practices make communication among players who have never taken the field together a greater challenge. "The more they can work together with different guys, when you do pick the finals starting lineup, or somebody just goes down, these guys come in and they have already practiced and played together," Davis said.

The fan-blog-radio preoccupation with depth charts spills over into overemphasis on the results of preseason games. Most fans are wise enough to ignore preseason final scores and focus on the first few drives, but even those "starter-versus-starter" series can be misleading. Teams show little of their playbooks, not just because they do not want opponents to see their strategies, but because too much intricacy gets in the way of the real goal of player evaluation.

Davis cited a simple example: say it's third-and-10 in a preseason game. A coach could blitz, or he could send a vanilla four-man rush with straightforward coverage on the receivers. A typical defensive coach will opt for the four-man rush because it allows him to watch how his defenders handle one-on-one assignments. "If we overload the blitz, and protection breakdowns happen, all of a sudden, [Eagles first-round pick] Marcus Smith has three sacks in a preseason game but doesn't get blocked. Versus: it's four guys, man rush, you gotta beat a tackle to win. You have a better evaluation."

The advantage extends beyond evaluating pass rushers. "Your cover guys have to cover a little longer when you rush four. So you are seeing how good your cover guy is," Davis said.

The obsession with preseason depth charts remains strong; a top prospect or free-agent signee relegated to the second team can become an easy talking point. In Cleveland, Johnny Manziel took his first starter's reps on Monday, and an all-points bulletin ensued. But Manziel has been working with "starters" since the beginning of camp. With no set receiver corps because of Josh Gordon's looming suspension, the Browns have been giving youngsters like undrafted rookie Tyler Gabriel and practice-squad project Charles Johnson reps with the starters. Veterans Nate Burleson and Anthony Armstrong have been among Manziel's "second stringers." 

Is Burleson really sinking on the Browns depth chart? Not at all. The Browns know what Burleson can do, so there is little need to evaluate him with the first team. Placing him among the backups helps Mike Pettine and Kyle Shanahan gauge the progress of both Manziel and a second-team defensive back. Of course, that second-team defensive back could well also be a starter in disguise: First-round pick Justin Gilbert has been working mostly with the reserves, and looking great.

There are similar situations in Philadelphia. Second-round receiver Jordan Matthews has been an impressive prospect since minicamps, but he was firmly embedded in the second team until well into Tuesday's camp session. Practice-squad dwellers Ifeanyi Momah and Will Murphy and veteran "slash" player Brad Smith were getting the first-team reps while Jeremy Maclin and Riley Cooper battle injuries. 

But Momah and Murphy are not really ahead of Matthews on anyone's long-range depth chart. Chip Kelly needs to see these youngsters against top cornerbacks, while Mark Sanchez needs a go-to target to make second-team drills viable. Matthews needs time to develop, but he does not need to be evaluated for his roster readiness.

Coaches are just not focused on the same things fans (and reporters) are watching, both in practice and in preseason games. "We want to see them perform well," Eagles offensive coordinator Pat Shurmur said of his expectations when the Eagles face the Bears on Friday night. "'Perform well' does not always mean 'this amount of production.' … We weigh whether they are doing their job extremely well and finishing plays"

Modern substitution packages are the final nail in the depth chart coffin. Coaches do not think of their offenses or defenses in terms of 11 starters and a bunch of backups. "We don't play 11. We play our best 15, 16 guys," Davis reminded reporters on Monday. The solution to the Jordan Mathews mystery at wide receiver went beyond just taking a longer look at bench players the team needs to make decisions on. Shurmur said Matthews is getting groomed primarily as an inside receiver, and staying with the second team allowed him to focus on the role he is expected to fill during regular season games.

Sure enough, when Matthews finally lined up with the starters for some Tuesday reps, it was on the inside. It was also news in a city that was beginning to wonder what was wrong with the second-round pick.

Obviously, preseason depth charts are not completely meaningless. A player stuck on the third or fourth string day after day will struggle to get meaningful reps. A rookie quarterback like Manziel must eventually see first-team reps, as Manziel has, if he hopes to start in the foreseeable future. And a deep demotion of a veteran player or top pick can sometimes be a motivational tactic. 

Most depth chart oddities are not messages, however. That undrafted rookie practicing with the starters probably did not leapfrog over the veterans just yet. And if the preseason pass rush doesn't strike fear into opponent's hearts, it may be because the defensive coordinator doesn't want his players in the best positions to look good.

And if you are still reading Tweets about quarterback completion percentages during 7-on-7 drills and trying to make sense of them, all of the reality checks in the world are not going to help you.