In a recent interview with Dave Zeitlin for MLSSoccer.com, Philadelphia Union manager Jim Curtin expressed a desire to bring back Maurice Edu and pair him with Carlos Valdes at center back. He's licking his chops at the thought of the All Star caliber center back tandem shutting down the likes of Kaka and David Villa. Curtin made the comment. "If you look at his record when we played center back, it was successful"

Indeed the Union record with Edu at center back looks successful. Under Curtin, Edu played thirteen games at center back and four in the midfield (he sat out one game with a red card suspension). When Edu was at center back the Union allowed just 1.08 goals per game. In the other five games they allowed 1.8 goals per game.

But before our collective chops are good an wet we should look at the impact on the offense. Because moving a nice player like Edu to center back would in theory have a detrimental effect on the the midfield. With the Union at center back, the team score 1.38 goals per game. When Edu was in the midfield the team averaged 2.0 goals per game.

And here is where these sample sizes can get us into trouble. If we believe that Edu was a key part of the Union's improvement on defense when comparing thirteen games to five, then we also have to believe that the gap he left impacted the offense, almost to the same degree.

A center back pairing of Valdes and Edu certainly does sound nice, and might just be the anchor of a top defense. But in the same article Curtin expressed a doubt about resigning Amobi Okugo. If Okugo and Edu are both out of the defensive midfield that would leave a major hole to fill just above the back four.

A Valdes/Edu pairing would sure ease some of the pain Union fans endured watching the revolving door of center backs last season. But such a move would beg larger questions and leave work left to be done.