PHILADELPHIA (973espn.com) - There are still two coordinator openings in the NFL and it's no coincidence that they are the result of Super Bowl attrition on the side of the football the head coaches from the big game specialize in.

For New England and Bill Belichick, that's the defensive side of the football in the wake of Matt Patricia moving on to the big chair in Detroit. For the champs and Doug Pederson, it's the offensive side after Frank Reich left to become the head coach with the Colts while his obvious heir apparent, John DeFilippo, decided calling plays in Minnesota would get him closer to his ultimate goal of being a head coach.

There are a few ways Pederson could go about replacing his two most trusted offensive assistants with the most likely being in-house, something he explained while appearing with another championship coach, Duke basketball coach Mike Krzyzewski, on the latter's SiriusXM radio show.

“There are guys that I think can be good coordinators," Pederson said. "Part of my coaching philosophy is to get them into your fold, so to speak, and groom them to take over some of these vital positions. "... I have some young guys on staff — I have Mike Groh, who has been in the league for a few years. Duce Staley is another one on staff.”

That would seem to point favorably to either the wide receivers coach or running backs mentor being elevated but there could also be a more unconventional approach looming.

"I have a long list of names that have come my way the last week or so," Pederson said. "Frank and I did a lot last year and obviously, I called the plays, and he and I put the game plans together."

Reich was also important in helping Pederson cobble together his offense by creating the structure, which is based on multiple play calls out of similar formations to help mask potential traits opposing defensive coordinators might be looking for.

Neither Groh or Staley have experience building a complex offense so Pederson might consider a unique structure with Groh taking over the passing game and Staley the running game with say, a senior offensive assistant with more seasoning helping out with the structure of the offense.

As an example, the Vikings just added Todd Downing, the former Raiders OC, as a senior offensive assistant to help DeFillippo in Minnesota.

Veteran coaches still out there who could fit that bill include former Detroit coach Jim Caldwell and ex-Seattle OC Darrell Bevell.

An in-house option could be Trent Miles, the former head coach at Indiana State and Georgia State, who Pederson quietly brought on last year as an offensive assistant and proved to be a valuable sounding board when putting together the RPOs that were such a significant part of the offense.

“I'm thinking through a lot of things and processing a lot of things right now," Pederson assessed. "I haven't ruled out not having an offensive coordinator. ... I'm not going to rush it. I'm going to make sure it's the right person, the right fit for what we are doing."

-John McMullen covers the Eagles and the NFL for 973espn.com. You can reach him at jmcmullen44@gmail.com or on Twitter @JFMcMullen