Where is the Patriots' fight?

MIAMI GARDENS, Fla. -- "When things don't go your way, you have to fight back. That's a challenge for all of us. At times I think we do. Other times, I don't think we fight very hard."

Those are the words of quarterback Tom Brady following the New England Patriots' 22-21 loss to the Miami Dolphins on Sunday.

Little more needs to be said.

The greatest quarterback in the history of the franchise succinctly summed up what ails the 2009 entry: It doesn't have a championship heart.

When the Patriots have a chance to bury the opposition, they can't call on a killer instinct, and when they take an opponent's best shot they don't consistently respond in kind. Once tough as nails and counted on to respond favorably in critical situations, the Patriots now crumble.

Maybe that can change over the final four weeks of the season and they can catch fire like the 2008 Arizona Cardinals, but that seems like wishful thinking after Sunday's self-destruction.

Perhaps if there were more players who took the loss as hard as Brady and receiver Wes Welker, the Patriots would have a fighting chance, but not every player seemed to feel the sting like those two. In one corner of what should have been a devastated locker room, a few were actually laughing.

One wonders if too much of the Patriots' championship soul has been stripped away. Gone are the Harrisons, Bruschis, Vrabels and Seymours.

Then there was Brady, who wore the pain on his face as he talked about the team needing to muster more mental toughness when adversity strikes. Once the Mariano Rivera of NFL closers, he seemed at a loss on Sunday to explain how the Patriots are suddenly so vulnerable in those critical game-ending situations.

In the Patriots' five road losses this season, Brady is completing just 52.9 percent of his passes in the second half, for 530 yards with two touchdowns and four interceptions.

"We're searching for the answers too," he said. "You have this feeling when you lose, it's an awful feeling. Coach always says you get what you deserve and in too many ways, you don't deserve to win when you make as many mistakes as we did."

The mistakes were across the board against the Dolphins, starting with Brady and his ill-advised throw into the end zone at the start of the fourth quarter, forcing a ball to Randy Moss that was intercepted by Miami's Vontae Davis.

Defensively, the lack of a consistent pass rush combined with poor coverage made Dolphins quarterback Chad Henne -- who attempted a whopping 52 passes -- look like a seasoned veteran.

And coach Bill Belichick's decision to go for it on fourth-and-1 late in the second quarter with a 14-7 lead and his team in line for an easy field goal try deserves scrutiny.

It's a familiar script, as the trademark of past Patriots teams is nowhere to be found. New England is 0-5 when playing in enemy territory, the latest loss coming after blowing a 14-0 first-half lead, then failing to come up with a stop on fourth-and-6 with the game on the line.

"It's really frustrating," said Welker, a bright spot with 10 receptions for 167 yards. "We've always been a team that's been able to overcome situations and fight through things, but we haven't been able to do that."

"You just have to be mentally tough to win on the road," safety Brandon Meriweather said. "Our team is not mentally tough like we are supposed to be."

In the big picture, all is not lost.

The Patriots (7-5) still hold a one-game lead in the AFC East over the Dolphins and Jets with four games to play -- versus Carolina, at Buffalo, versus Jacksonville and at Houston. They had a chance to put the Dolphins behind them Sunday, but as has been the case throughout the season, they couldn't deliver the knockout blow.

"We're in a one-game playoff now every week," linebacker Jerod Mayo said. "It's like having a seven-point lead in the fourth quarter. We just have to come up with plays."

Given the way the Patriots have played this year in those situations, that's not a very comforting scenario.

Mike Reiss covers the Patriots for ESPN Boston. You can follow him on Twitter or leave a question for his weekly mailbag.