The Jets may be down, but they say they're not defeated.

After their fifth straight loss, they reiterated that their season is not lost.

"We're going to keep fighting -- no matter the situation, no matter how many points we're down,'' linebacker David Harris said Sunday after their 31-17 loss to the Broncos at MetLife Stadium. "It's not in our makeup to quit. I'm proud of everyone in this locker room, but we've got to find ways to win.''

And therein lies the problem with these Jets (1-5).

For all the fight they've shown in spurts this season, they haven't won a game since Week 1 against the Raiders, who still haven't beaten anyone. The Jets have managed to lose games because of myriad reasons: erratic quarterback play, porous pass protection, defensive lapses and even an ill-advised timeout call from the sideline. Sunday, it was no different. Several miscues combined to produce an effort that just wasn't good enough to lead to victory against Denver (4-1).

Their running game was virtually nonexistent (the Jets' 31 rushing yards were the lowest output in Rex Ryan's five-plus seasons). Their special-teams play was uneven. Their offense was "kind of stagnant,'' according to defensive end Muhammad Wilkerson.

Yet somehow they managed to make it a ballgame against a future Hall of Fame quarterback.

Trailing 24-7 late in the third quarter, the Jets scored 10 unanswered points to re-energize the dormant home crowd. Nick Folk's 30-yard field goal pulled them to within 24-10 with 36 seconds left in the third. When Geno Smith threw a 2-yard touchdown pass to Eric Decker with 7:56 to go in the fourth, it was a seven-point game.

But after the defense forced Denver to punt from its 15, Smith and the offense failed to score. The second-year quarterback later killed the slim hope of a dramatic upset when cornerback Aqib Talib intercepted a pass and returned it 22 yards for a touchdown with 15 seconds left.

Peyton Manning entered the game five touchdown passes shy of tying Brett Favre's record (508) and threw three, including two to tight end Julius Thomas. The Jets made Manning uncomfortable in the pocket early but he settled down, completing 22 of 33 passes for 237 yards.

Although the Jets' win-loss record indicates they're close to midseason irrelevancy, they think they're on the verge of a breakthrough.

"Every week you want to win,'' said linebacker Demario Davis (11 tackles). "And when the tide turns, I think it's going to turn very strong.''

"It's not about what people say,'' added Wilkerson (one sack, eight tackles). "I feel like we fought hard the whole game. We were behind a wall, I felt like we cracked that wall today, and hopefully we can break it come Thursday night.''

Fans will be upset for days about this latest loss, but the Jets, who lost cornerback Dee Milliner to a possible season-ending Achilles injury, don't have time to wallow. They have to prepare for a prime-time matchup with the Patriots (4-2) Thursday in Foxborough.

And the Jets still believe their season is salvageable -- even if few share that sentiment.

"One thing I know about this team is that we're fighters,'' said Smith (23-for-43, 190 yards, two touchdowns). "This is our job, so the passion is going to be there regardless.''

But that doesn't mean they're not frustrated.

"Do you see my face?'' Sheldon Richardson said. "Frustrated, right? That's all you need to know. It's frustrating to lose.

"I'm not a loser, none of us are losers, so losing is frustrating.''

Moral victories don't count in the Jets' locker room, Leger Douzable said. "It's wins and losses. That's all that matters in this game,'' said the defensive end, who recorded his first sack.

"Going on the road to play Thursday is a big challenge, but I think we have the men in that locker room,'' Ryan said. "We're going to go up there and play the best game we possibly can. It would be nice to find a way to win.''