Marshon Lattimore once talked about last year about how he approaches every game as if it is going to define who he is as a player.

It doesn’t matter how many hits you have in the bank. If the next one is a dud, people are going to talk about it until the next week. After watching the Saints stumble through a stunningly inept defensive performance during Sunday’s 48-40 loss to Tampa Bay, it seems Lattimore might be onto something.

It’s possible this team just needed to be “slapped in our face," as Lattimore put it, after a summer full of hype and love. But without any other deposits to pull from, this performance is the only thing we can judge. So after spending the summer talking about how they were going to “prove them right,” this defense will go into next week’s game needing to “prove them wrong.”

A standard loss wasn't unfathomable. The way the Saints lost on Sunday was, because it destroyed just about everything we came to believe about this defense last season. The performance would make more sense if the Saints somehow entered an alternate reality where this game was actually last year's Week 3 game after listless performances against Minnesota and New England. It makes no sense as the continuation for what is supposed to be an ascending defense ready to establish itself as one of the better groups in the NFL.

Here is how bad it was: Ryan Fitzpatrick, the journeyman backup quarterback who entered with a career quarterback rating of 79.9, completed 21 of 28 passes for 417 yards with four touchdowns and rushed 12 times for 36 yards, including a 12-yard gain on third-and-11 late in the fourth quarter that sealed the win.

The last run was the killer. As bad as New Orleans played, it put itself in position to get the ball back with a chance to tie the game if it could make one more stop. But after watching Fitzpatrick tuck and run several times, the Saints let him do it once again.

The problem wasn't that the defense was unprepared for him to run. The defense wasn't ready for the way he was running.

“Clearly we wish we could have had a better plan,” defensive end Cam Jordan said. “Clearly we wish we would have had a spy on the quarterback. From film we previously saw, we figured he’d escape the pocket by stepping straight up. He got a little more lateral this time than he did before.”

But that was just one problem. Everything was an issue, which tends to be the case when a defense allows 529 yards and six plays of 30 or more yards. Early on, the run defense wasn’t what it should have been, which made it harder to rush the passer. And the inability to keep Fitzpatrick in the pocket created a double-edged sword: the Saints needed to be conservative enough not to create running lanes but still get there fast enough to affect the quarterback's throws.

The Saints didn’t use the full-on “crush rush” philosophy it employs against players like Panthers quarterback Cam Newton, but there were some elements at play. The problem is, the pass rush never showed up at all. Now there were certainly more than thee examples, but it felt like the only times New Orleans got to Fitzpatrick was when Jordan batted down a pass in the first half and when defensive tackle David Onyemata and defensive end Marcus Davenport got whistled for roughing the passer.

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“He wasn’t really going through his progressions, really third, fourth, maybe fifth option on routes,” defensive tackle Sheldon Rankins said. “He was one, maybe two (reads). He was able to find lanes.”

And there exists one of the big issues from Sunday. Without much pressure, Fitzpatrick was able to pick apart the secondary. And with the secondary not covering well, the pass rush didn’t have time to get after the quarterback. It's hard to do one thing well when the other area of the defense isn't clicking. It's impossible when both elements are struggling.

The secondary having a rough day was probably one of the more surprising outcomes of the game. The Saints were rough against the run last year (4.4 yards allowed per carry), and the pass rush has never been dominant. The strength of this defense is supposed to be the secondary. It wasn’t on Sunday.

The trouble started early when the Saints struggled to defend against a bunch formation (an ongoing issue), and cornerback Patrick Robinson and safety Vonn Bell seemed to get mixed up on a switch, allowing DeSean Jackson to run free for a 58-yard touchdown. The team then got beat on a pick play and struggled with individual matchups.

Cornerback Ken Crawley was on the wrong end of several big plays and almost gave up another but was lucky Fitzpatrick overthrew wide receiver Chris Godwin after the cornerback slipped and fell on third down. And after holding Tampa Bay receiver Mike Evans to 38 combined yards while in direct coverage during two games last year, Lattimore gave up at least 96 yards on four receptions to him Sunday, including a 50-yard touchdown on a go route.

Lattimore didn’t seem to take it personally.

“Yeah, he had some plays, he won the 50-50 balls,” Lattimore said. “But it is what it is; it’s the NFL. Everybody’s gonna have their day.”

The Saints did not have their day on Sunday.

This group is still good enough to rebound and turn this into a footnote, much like it did after the Minnesota game a year ago. But it will take time for it to fade away.

For now, the Saints will be doubted in some corners until there is enough reason to believe again. If Sunday proved anything, it is that this is a new year with a different story to tell. If they want the narrative to change, the Saints are going to have to prove it against Cleveland.

Follow Nick Underhill on Twitter, @nick_underhill.​