The Chicago Bears have spent the entire offseason, from Black Monday up until after the draft a few weeks back, making over their organization and their roster.

The outgoing regime of Phil Emery and Marc Trestman left a lot of holes and deficiencies on the roster, as well as few games won. The Bears needed an infusion of youth, talent, and coaching, and new GM Ryan Pace has done his best to do just that.

There is little doubt that new head coach John Fox - the first veteran head coach hire the franchise has made in decades - and his staff are an immediate upgrade to the outgoing one. Fox's coaching philosophies seem directly to mesh with the Chicago Bears' historic team make up: defense first and a powerful running game.

However, a strength of Fox also seems to be his willingness to take on new ideas and adopt new ways of playing and scheming for his football team.

He brought in defensive coordinator Vic Fangio, who will run a 3-4 system that Fox never has used before. In Denver with Peyton Manning, Fox allowed his coordinators to play to the quarterback's strengths and air the ball out more than his teams were known to do.

This is arguably the most experienced and coaching staff in Chicago history. While they have fewer former head coaches than certain Lovie Smith staffs, they make up for it with results (Fangio has coached four top 10 defenses, Gase two top five offenses, and Fox seven playoff appearances as a coach). For a little perspective you have to go back to 1990 and the past FIVE Bears head coaches to get seven playoff appearances.

That said, no one is expecting a one year turnaround. While Fox has been known to do such turnarounds and even a four-win improvement could put them on the cusp of a Wild Card berth, it seems unlikely with the sheer amount of rebuilding necessary.

Before considering the team itself, a quick look around the division reminds fans that the Bears face an uphill battle in their own division, where the Packers are the four-time defending NFC North Champion and the Detroit Lions made the playoffs last season after sweeping the Bears. The Vikings are a young and feisty team as well.

Elsewhere, the NFC landscape has a number of very good to contending-type teams with Seattle, Arizona, Dallas, Philadelphia and Carolina all having been in on the cusp of the postseason recently.

Looking at the team though, even with all the additions and moves Pace and Fox have made, could it be enough?

Several big question marks remain at the quarterback, wide receiver, offensive line, linebacker and safety positions.

What is the biggest thing holding the team back? Last season it was easily the coaching staff as, in all facets of the game, the team played uninspired and just horrible.

Neither side of the ball is without its issues. Heading into last season it seemed the defense was the only issue after a record-setting offensive year in 2013. However, questions persist around QB Jay Cutler, and running back Matt Forte isn't getting any younger. Can Alshon Jeffery be a dominant No. 1 without Brandon Marshall playing across from him? Can the WRs be very effective with a rookie playing a significant role? What about the right tackle position?

On the other side of the ball, who will be the linebackers for Fangio's 3-4? Will players like Lamarr Houston and Jared Allen be effective in positions they've never played, truly? Can the coaches find playmaking linebackers from Christian Jones, Shea McClellin and Jon Bostic?

The biggest question mark on defense continues to be at safety. The Bears brought in Antrel Rolle, but behind him there is little depth or experience.

In a division with Aaron Rodgers, Matthew Stafford, Calvin Johnson, Jordy Nelson and now Mike Wallace and the up-and-coming Teddy Bridgewater, pass defense will need to be a strength.

To me that is the biggest thing holding this team back. We've seen Cutler lead a playoff run, we've seen him be a effective player in the right offense, with the right cast and limitations on him. We've seen Forte thrive in a number of systems, with a number of back ups vying for carries. Fangio and Fox can surely coach up the front seven and Kyle Fuller, Tim Jennings and Alan Ball can form a menacing cover trio, but can Rolle, Brock Vereen, Ryan Mundy and/or rookie Adrian Amos provide the over-the-top protection and stop the deep balls that have plagued Chicago the past couple of seasons?

That is the biggest thing holding the team back to me.