MOBILE, Ala.

If the New Orleans Saints are going to better their 7-9 record next season, the improvement probably won't come through blockbuster free-agent signings.

With a salary cap standing at roughly $156 million, the 2016 Saints are currently over the projected NFL limit that is reportedly expected to settle at between $150 million to $153 million. Even should the Saints create space by restructuring the contract of quarterback Drew Brees – whose cap charge alone stands at $29.6 million – New Orleans is still unlikely to have the room to spend big on outside talent.

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Saints head coach Sean Payton acknowledged as much Wednesday during an interview with co-host Mark Dominik and me on SiriusXM NFL Radio. Payton also said the draft would be the primary avenue in which the team tries to upgrade its roster.

"Mickey [Loomis, Saints general manager] and I have always looked closely at what's a must area, a potential area that we might look at in the free-agent market," Payton said while scouting college talent at the Reese's Senior Bowl. "Maybe it's the market down the road.

"We've had some players really fit roles for us in the latter part of free agency. This year shouldn't be any different."

Defense is one area that Payton hopes is different for the Saints than last season when the unit allowed the most touchdown passes (45) in NFL history while also surrendering a league-high average of 29.8 points. The struggles led to the firing of defensive coordinator Rob Ryan after New Orleans fell to 4-6.

Payton is encouraged by how the unit responded under replacement Dennis Allen, who was officially named to the defensive coordinator position earlier this month.

"I think any midseason change of that nature is always challenging and difficult because a culture begins that very first time we're in OTAs and (continues) in minicamp and training camp," Payton said. "But I would say this: For the last half of the season, we were playing better defensive football in winning three of the last four games we played against some good teams.

"I think there's a confidence level on that side of the ball heading into this offseason. Obviously, there are some pieces we need to still fill but D.A. has a presence about him. We've worked together before. I think all things considered he did a real good job."

As for the offense, Payton said Brees "had one of his better years" in 2015 but also admitted "there's always that little bit in you that is unsatisfied with a certain element."

"I think we've got to be a little more consistent running the football," said Payton, whose team's rushing average of 93.2 yards was 20 yards less than during the 2014 season.

"Whenever we've been real good that's been something we've been good at. It gets overshadowed sometimes."