One of the primary reasons why the Philadelphia Eagles were able to acquire two-time Pro Bowl linebacker DeMeco Ryans one year ago was because Ryans became expendable in Houston once the Texans transitioned from a 4-3 defense to a 3-4.
The Eagles have over $6 million committed to Ryans, who is easily the team's best linebacker, over each of the next three years.
Trent Cole is their best defensive player, period. Also a two-time Pro Bowler, he signed a six-year, $59 million contract with the Eagles less than a year ago.
Those two key players, along with the fact that Philadelphia has invested heavily of late in adding depth along the defensive line, make the notion that the Eagles might consider switching from the 4-3 to the 3-4 sound ridiculous.
Neither Ryans nor Cole are natural fits in a 3-4 scheme, but new Eagles head coach Chip Kelly appears to be leaning that way in spite of those major caveats.
Kelly wouldn't commit to either formation during his introductory press conference on Thursday, but Jeff McLane of the Philadelphia Inquirer had this tidbit in an article published Wednesday:
Kelly favors an aggressive, attacking-style defense and will likely change the Eagles' scheme from a 4-3 to a 3-4, a source familiar with the coach's thinking said.
A report by CSN Philly also points to Kelly bringing in Georgia defensive coordinator Todd Grantham to run the D. Grantham has a 3-4 background.
But Kelly has also said on several occasions that the personnel should dictate what a coach does schematically. Here are his own words, via CSN Philly's Reuben Frank:
Anything you do has to be personnel driven. You have to adapt to the personnel you have. There's a lot of great offenses out there, but does it fit with the personnel you have? The key is making sure what you're doing is giving your people a chance to be successful.
Kelly is discussing offense there, but the same can and should be applied to defensive personnel and schemes. Cole and Ryans aren't built ideally for the 3-4, the Eagles don't have a nose tackle on the roster and they lack depth at the linebacker position.
I don't think there's anything wrong with preferring the 3-4, but I don't believe it would be prudent for Kelly to force a change that doesn't make sense in the short term.
Instead, he should focus on easing into the 3-4 over the course of several seasons by drafting and acquiring the types of players that might be more effective in that style of defense in 2014 and beyond.