Flip of a coin. That’s the Vikings’ success rate on third-down defense.

Actually, they’re slightly worse than that after Green Bay’s Aaron Rodgers carved them up Sunday night. Opponents are converting 51 percent of their third-down opportunities against the Vikings, which is easily the worst mark in the NFL.

For context, the Vikings are on pace to become the first team since the 1995 Cleveland Browns to allow 50 percent conversions on third down.

“We’re so bad right now on third down on defense,” coach Leslie Frazier said in a moment of brutal honesty Monday.

Myriad deficiencies have contributed to the Vikings’ 1-6 record, and the defense’s inability to get off the field at a reasonable rate on third down belongs prominently on that list.

The Vikings rank last in the NFL in time of possession, a bad sign for a team that’s built around a ball-control offense. Their defensive issues are partly to blame.

A season-long sore spot became a full-blown nightmare in a 44-31 loss to the Packers. Green Bay converted 13 of 18 third-down chances, scored on eight consecutive possessions and did not punt once all game.

The Vikings struggles on third down enabled the Packers to consume 40 minutes, 54 seconds in time of possession. The Vikings ran only three offensive plays in the third quarter.

“We were out there for a long time,” cornerback Chris Cook said.

Rodgers was particularly masterful on third down, converting 10 of 10 passes for 172 yards and two touchdowns. He also rushed three times for 29 yards on third down, all resulting in first downs.

“It’s not pretty and unfortunately it has been the flavor of the month for us,” linebacker Chad Greenway said. “We haven’t been good at all on third down across the board.”

Now, the scary part: it could actually get worse. The Vikings still must play seven of the top 11 highest-scoring teams in the NFL in their final nine games, starting with the Dallas Cowboys on Sunday in Arlington, Texas.

The Vikings could be without three of their four starters in the secondary, too. Safety Harrison Smith already is on injured reserve, and Cook (hip muscle strain) and safety Jamarca Sanford (groin strain) were injured Sunday.

Frazier said the coaching staff will spend the next few days evaluating every facet of their third-down approach to determine if there’s anything that can be done to fix that area. However, he admitted that “I don’t know what you can do personnel-wise” this late in the season.

“You’ve got to look at how we’re doing it, what we’re doing schematically, and also the people that you’re asking to do certain things,” he said. “Any time a team gets 72 percent conversion rate, that’s time to really do some re-evaluation.”

Frazier and several players credited Rodgers’ brilliance in dissecting their breakdowns. In particular, cornerback Josh Robinson and Green-way had tight coverage on Green Bay’s first two scores, but Rodgers managed to thread passes to Jordy Nelson for 11-yard and 76-yard touchdowns.

“You go back and look at film and guys were in perfect position, but Aaron Rodgers finds a way to get the ball to [his receivers],” Sanford said. “The passes he throws, there’s no way you can really defend it when it comes down to it. The throws he was making, most quarterbacks would look that way and would be like, ‘Oh, that guy is covered.’ But he finds a way to get the ball in there.”

Frazier made that point to Robinson, who has struggled all season in coverage.

“I told Josh, ‘I don’t know if myself or any of the other coaches could tell you to do anything different from what you did,’ ” Frazier said. “You have to give [Rodgers] some credit, give their offense some credit. But then we still have to find ways to keep them out of so many manageable third downs.”

Even that doesn’t guarantee success, though. On third-and-16 late in the third quarter, Rodgers eluded Brian Robison’s pass rush, scrambled to his right and fired a pass back across field. Jarrett Boykin caught it and still had time to lunge twice for a first down.

“Our guys are doing the very best that they can,” Frazier said. “We have some young guys on the back end that are battling, they’re getting better, they’re making some headway. So I don’t know if there’s very much you can do there. We have to look at what we’re asking them to do and how can we help them to be better at what we’re asking them to do.”