JACKSONVILLE – And, poof …

There went the Jaguars' momentum – for now, anyway. And the fun that felt so real?

That went away, too – or, at least it got put on hold.

That wasn't supposed to be Sunday's storyline, not the way this team had been playing. But that's what happened.

The Jaguars didn't play well, and didn't take advantage of opportunities. As a result, they lost a game they almost certainly could have won, 31-25 to the San Diego Chargers in front of 59,477 on a cloudless late-November afternoon at Everbank Field.

A day that began with a buzz ended with the Jaguars having done too many things they have done too often this season. Because of that, the result was too familiar. And because of that, Jaguars Head Coach Gus Bradley immediately after the game was at a podium at the 'Bank saying familiar words.

"We didn't make enough plays today," Bradley said after the Jaguars outgained the Chargers but never held possession in the second half with a chance to take the lead.

"There were plays out there. We left them out there."

Bradley summed up the game moments later.

"The big story would probably be the red zone," he said.

Well, yeah …

The Chargers had five possessions inside the Jaguars 20. Their savvy, veteran quarterback – Philip Rivers – turned those into four touchdowns and a field goal.

The Jaguars had four such possessions. Their young, second-year quarterback –Blake Bortles – turned them into three field goals and a late touchdown, and twice in the red zone threw passes when beyond the line of scrimmage.

Bortles called the red-zone offense frustrating.

"It's really just a lack of execution," Bortles said. "We have to continue to improve on that."

Wide receiver Allen Robinson put it in perspective when asked afterward if he was surprised the Jaguars hadn't played better considering the circumstance. This was a team that entered Sunday having won three of four games, a team that also entered Sunday a game out of first place in the AFC South.

"I wouldn't say we played poorly," Robinson said. "The difference in the game was when we got in the red zone we had three field goals, one touchdown; they had four touchdowns and one field goal.

"That's the difference in the game right there."

 And you know what? Robinson was spot on.

You can break down all of the other stuff you want – Bortles' late first-half interception, the Jaguars' surprising inability to run effectively, the inability to force a turnover – but Sunday came down to red zone on both sides of the ball.

Rivers threw four touchdown passes and all four came in the red zone. Two were to tight end Antonio Gates in a devastating 65-second span in the final two minutes of the first half. When San Diego had chances, Rivers and his well-earned reputation as one of the NFL's elite quarterbacks took full advantage.

As for the Jaguars, they showed again what has been the case all season.

They can move between the 20s. On that front, they are a vastly improved offense from a year ago. But they entered the game in the bottom quarter of the league scoring touchdowns in the red zone, and had converted just three of their last 11 opportunities inside the 20.

The simple truth is you don't beat veteran quarterbacks such as Rivers kicking field goals.

The Jaguars knew that entering the game. They really know it now.

As for what Sunday means, this game – this one loss – isn't necessarily an end to anything, but it sure makes playoff talk seem like a distant memory. Still, one game isn't a sweeping indictment. How this season is assessed still will be determined at the end of the season and not in late November.

There are still plenty of signs of growth, and in a sense, Sunday's outcome wasn't a shock because no Jaguars loss is all that surprising this season. They're still a young team, still with a developing quarterback. They're still a team that struggles to rush the passer. When you're those things it's difficult to be well ahead at the end of games, and close games can go either way.

It's just that this one felt like it had a chance to be different, and that's what made it deflating. With the Jaguars playing a team that had lost six consecutive games, Sunday was by any measure a huge opportunity squandered.

And wasn't that just too bad, that squandering? What a different feel the day could have had. The pre-game buzz was real. The energy was real. The 'Bank was in a very real sense ready to keep going crazy. It was ready to keep believing. It was ready to have fun. It didn't. Instead, there was a poof and a discernable flow of air leaving the 'Bank.

And with it, the fun that could have been December at the very least got put on hold.