Merry preseason, everyone. It’s been a long offseason, but football is finally gearing up again and to celebrate I’m rolling out a new series on TSR entitled “2010 NFL Question Marks,” where I discuss one or two of the biggest concerns that teams have heading into the new season. Granted, some teams have more issues than others, but I’ll primarily be focusing on the biggest problem areas. Today I’ll be discussing the lack of depth the Eagles have in their secondary.

Truth be told, the Eagles are in pretty good shape entering the season. The question on everyone’s mind is whether or not Kevin Kolb can replace Donovan McNabb, but I wouldn’t necessarily deem the quarterback position a weakness.

Nor would I say secondary is a weakness either. I like the starting four of Asante Samuel, Ellis Hobbs, Quintin Mikell and highly intriguing rookie Nate Allen. But after trading Sheldon Brown to the Browns in the offseason, the depth behind those players is now where the concern lies.

Hobbs, who keep in mind is coming off neck surgery, is expected to return kickoffs once the regular season starts. If he were to go down with an injury, it would leave the Eagles with Macho Harris, Joselio Hanson or fourth-round pick Trevard Lindley at the cornerback position opposite Samuel. And none of them have proven that they can be starters at this level. (Although to be fair, Lindley is only a rookie.)

And what if Allen struggles as a first-year starter? All indications are that he’s a stud in the making, but the regular season hasn’t started yet and thus, he hasn’t officially been tested. After losing his job to Harris last season and battling injuries throughout the year, can the Eagles get by with Quintin Demps if Allen can’t produce as a rookie?

Of course, most of this is hypothetical, which is why I’ll reiterate that I don’t think the Eagles have any predominant weaknesses. Again, I think their starters are solid and Allen has a legitimate chance of winning the Defensive Rookie of the Year award if he can live up to expectations.

That said, this is still a thin secondary and Andy Reid better hope that this unit can stay healthy throughout the year. An injury to a starter could derail Philly’s chances of returning to the postseason.