One of the questions head coach Chip Kelly and his offensive coaching staff have considered throughout this offseason, no doubt, is this: How can this Eagles offense, one that was so prolific in 2013, become even more explosive, more complete and more efficient in 2014?

The Eagles have made some interesting personnel moves in the months that have passed, releasing wide receivers Jason Avant and DeSean Jackson and in the process saying goodbye to their best slot receiver of the last decade (Avant) and a receiver who was one of the most productive and explosive in the NFL (Jackson) since he was drafted in 2008. They have also added running back/receiver/"move" weapon Darren Sproles, who is expected to be utilized in a variety of creative ways by Kelly and the coaching staff.

The offense has exchanged veteran quarterbacks with the Jets -- Michael Vick goes to New York and Mark Sanchez comes to Philadelphia -- and that's been pretty much the extent of personnel changes within an offense that clicked like few others in the NFL in the first year of a new scheme with a new coaching staff.

So what's next?

Kelly knows that those defensive coordinators the Eagles face this season have spent countless hours studying 2013's performance, looking for tips and tendencies and any way to gain an edge on the Eagles offense. He undoubtedly will have his counter moves prepared as Kelly moves the Eagles offense into Year 2 of the scheme.

The Eagles must be better on offense. That is a point nobody argues. Kelly said it himself in a way when he met reporters at the NFL's Annual Meeting in Orlando, FL and suggested that "every" phase of the team needs to be better. It's hard to argue that point. The Eagles had a bounce-back season in 2013 and won the NFC East with a 10-6 record and, yes, that was extremely encouraging. But the goal for every team is to win the Super Bowl.

To do so, the Eagles need to be a whole lot more prolific in a playoff setting than they were in the loss to New Orleans. The Eagles scored 24 points in the game, but the performance in the first half, when they had a chance to create some distance and force the Saints into a game of catch up, was lacking. The Eagles gained just 122 total yards of offense in that first half, just 35 of them on the ground. Quarterback Nick Foles completed 13 of 18 passes, but the air game put up only 98 yards. .

Philadelphia scored only seven points in the game and failed to take full advantage of an average drive start at its 34-yard line and a defense that forced two Drew Brees interceptions.

While the Eagles aren't going to overhaul the scheme, they're going to make some adjustments and will unveil them through the course of the season ahead. From a personnel standpoint, the Eagles have some legitimate question marks at wide receiver given the decisions to release Avant and Jackson. Namely, who takes up the slack in the slot? And, how do the Eagles replace the production Jackson provided last year as he thrived in his first exposure in the offense?

The Eagles could very well add to the mix in the draft on May 8-10, and they also think they've got some pieces in place that are going to step in and step up and make the offense perform at a high level than last season.

Jeremy Maclin expects to be full go for training camp after missing 2013 with a knee injury. He's a bigger body to team with Riley Cooper, and Maclin's speed as a deep threat and his run-after-the-catch ability should fit in nicely with the offense. Maclin had terrific success in the team's spread-it-around approach prior to his injury and there is every reason to think that he will be the same kind of threat, including a bona fide playmaker in the red zone, as he was from 2009 to 2012 when Maclin became one of only eight players in NFL history to record 55 catches and 750 yards in each of his first four seasons.

Then there's tight end Zach Ertz, who caught 36 passes and 4 touchdowns as a rookie. Ertz has enough speed to get down the field and his big body creates a tough defensive matchup for defenses, and he could see time in the slot as the Eagles look for more size inside.

Sproles will certainly be an option to use. He's a prolific pass receiver and one of the toughest players in the league against whom to match up in coverage. The Eagles are going to put Sproles in space and dare defenses to cover him with a linebacker or a safety. They'll use both Sproles and LeSean McCoy, both of whom are outstanding in the passing game, out of the backfield on screens and quick flat routes and bubble passes.

As the roster looks now, and by design, there are options for the offense. The running game is in a great place with McCoy, the league's leading ground gainer last year and in the prime of his wonderful career, leading the way. Sproles will be an excellent change-of-pace back. Bryce Brown, in his third season, has an abundance of talent and the Eagles want to see him blossom on a consistent basis. Chris Polk and Matthew Tucker are developing young talents who are fighting for playing time.

Nick Foles benefits by taking the reps from day one in practice as the starter, so his timing and comfort level in the offense will be at its peak by September.

The major question for the offense revolves around the wide receivers. How does the team feel about the depth behind Maclin and Cooper, who became a go-to option replacing Maclin as a starter last season? Is this wide receiver-rich draft an area the Eagles will focus on in May? Can they add an immediate contributor or two at wide receiver between now and, say, August?

Or are young players like Damaris Johnson and B.J. Cunningham and Jeff Maehl and others part of the vision Kelly and his staff have for the passing game?

We'll know a whole lot more when the draft ends, of course. It's safe to feel confident in Kelly, one of the game's forward thinkers. He is as demanding as any coach, and there is no sense from him that the Eagles have "arrived" offensively.

Yeah, the Eagles are going to push for more from the offense. We've seen the struggles offenses have had in the first year of head coaches in the past -- Andy Reid's 1999 Eagles were among the league's worst offenses, for example -- and so for the Eagles to do what they did in Year 1 of the Kelly Regime and overcoming the loss of Maclin and some injuries at the quarterback position, was quite remarkable.

Many of the pieces are in place here. How much more do the Eagles think they have to add?