EDEN PRAIRIE, Minn. — Coach Mike Zimmer is a big believer in inspirational signs. He has hung them where players have no choice but to see them each day as they sit in meeting rooms, lift weights and head for practice.

Early last week, he pointed to one of his favorites: “Tough teams win in the fourth quarter.”

That, he said, was the target heading to Miami a week after the Vikings blew an early 14-point lead and gave up the winning points in the fourth quarter of a 16-14 loss to Detroit.

On Sunday, after the Dolphins scored 23 fourth-quarter points to beat Minnesota 37-35, Zimmer realized he still has a ways to go to meet the standard of his favorite sign.

For the second straight week, the Vikings started fast but blew a 14-0 lead. They led 17-7 at halftime but collapsed in the second half in an uncharacteristic display by a unit that was on the verge of cracking into the top 10 in the league in fewest yards allowed.

The Dolphins scored 30 second-half points, recording touchdowns on all four offensive possessions. Three of them were 80-yard drives. Dolphins quarterback Ryan Tannehill threw for 396 yards and a career-high four touchdowns on 35 completions.

“That pretty much sums up the season right there,” said safety Harrison Smith, referring to fourth-quarter collapses at Buffalo, Detroit and Miami. “We’ve had opportunities to close, and we haven’t closed enough times. It’s something we’ve got to fix.”

Had the Vikings been able to hold those three fourth-quarter leads, they would be 9-6 and in the playoff picture instead of 6-9 and only half a game better than last year’s 5-10-1 season. Of course, the Vikings also won two games in overtime, so they’ve had some good fortune late in games as well.

The best news, however: Regardless of record, the Vikings have reason to believe they’ve finally found the young franchise quarterback that this team has lacked for years. Teddy Bridgewater was outstanding, completing 73.1 percent of his passes for two touchdowns and a 114.1 passer rating. His one interception bounced off a running back’s hands.

On third downs, Bridgewater completed 6 of 7 passes for 97 yards and a touchdown in a poised performance that helped him earn trust from teammates and coaches.

Based on the full body of work this season, the defense also will be solid. But it sure wasn’t as tough down the stretch as Zimmer had in mind when he hung that sign.

“We couldn’t cover anybody,” Zimmer said. “We didn’t rush and we didn’t cover. So that’s a pretty hard combination.”

NOTES: LB Chad Greenway started Sunday’s game less than two days after his father, Alan, died of leukemia. Greenway injured his right knee in the third quarter and wasn’t able to continue. “That’s not what I had in mind flying to Miami and playing this football game,” Greenway said. “It just makes matters worse.” … SS Andrew Sendejo started in place of Robert Blanton, who was healthy again after missing the previous week’s game because of leg injuries. Sendejo left to be evaluated for a concussion, and Blanton finished with a game-high 11 tackles.

REPORT CARD VS. DOLPHINS

–PASSING OFFENSE: B — Teddy Bridgewater took another step toward assuring people that he’s capable of being the young franchise quarterback this franchise has been starving for. He completed 73.1 percent of his 26 passes, posted a 114.1 passer rating, threw two touchdowns and had an interception that wasn’t his fault because it bounced off running back Matt Asiata’s hands. Bridgewater again showed poise under pressure, completing 6 of 7 third down passes for 97 yards, a touchdown and three first downs. The line struggled but fought hard with three backups in the game.

–RUSHING OFFENSE: B — Nothing flashy, but Asiata did set the tone early in the game, powering his way through the Dolphins on the Vikings’ first possession. He touched the ball on eight of the first 10 snaps, including the first of two rushing touchdowns. Joe Banyard had the best run by a running back, blasting through a hole for 16 yards on third-and-5 deep in Vikings territory late in the first half. That changed the game. The Dolphins had called all their timeouts to set up good field position. Then it was the Vikings who were spending timeouts to set up a field goal that gave them a 10-point lead.

–PASS DEFENSE: F — Mike Zimmer’s normally reliable defense absolutely collapsed in the second half. The Dolphins touched the ball four times in the second half and scored all four times. Three of the drives were 80-yarders. Cornerback Captain Munnerlyn gave up passes of 40 and 41 yards on two of those 80-yard drives. Ryan Tannehill had 396 yards on 35 completions and a career-high four touchdowns. The Dolphins also converted 9 of 13 third-down situations.

–RUSH DEFENSE: C-minus — The Dolphins were too busy torching the Vikings’ defense to post outrageous running numbers. But Lamar Miller did average 4.8 yards on 19 carries. The Dolphins also topped 100 yards (116) and averaged 4.1 a carry. In other words, the balanced attack sure helped Tannehill in the passing game.

–SPECIAL TEAMS: F — In a span of four minutes at the end of the game, the special teams went from an A and the reason the Vikings would win to an F and the final reason they lost. Using a Miami personal foul on a two-point conversion, the Vikings kicked off from the 50-yard line with just under five minutes left. Blair Walsh popped a ball up perfectly to the 1-yard line, forcing the Dolphins to return. A fumble recovered by the Vikings set up a touchdown run and a seven-point lead on the next snap. But none of that mattered when normally reliable long snapper Cullen Loeffler one-hopped a snap that punter Jeff Locke scrambled to get off. He couldn’t before the ball was blocked out of the back of the end zone for the game-deciding safety with 41 seconds left.

–COACHING: C — Give Zimmer and his staff credit for keeping a non-playoff team engaged and intense on the road a few days before Christmas in South Beach. The Vikings built a 14-0 lead on the road for the second time in two weeks. But they also blew one for the second time in two weeks. The offensive game plan was solid again and meshed with Bridgewater’s strengths and the line’s weaknesses. But defensively, the Vikings collapsed in the second half. The defense gave up 28 of the 30 points on four touchdowns.