As the Vikings begin the long process of trying to return to the NFC Championship Game — and win it — in 2019, they're forced to contend with the questions the Philadelphia Eagles raised about their top-ranked defense by racking up 456 yards and 31 offensive points in the conference title game on Sunday.

The Vikings hadn't given up that many yards in a game since Dec. 21, 2014, when they allowed 493 in a 37-35 loss to the Miami Dolphins at the end of their first season under Mike Zimmer. The fact their defense was pierced so easily on Sunday, by backup quarterback Nick Foles with a trip to the Super Bowl on the line, will add another layer to the self-scouting process Zimmer already had planned for the offseason.

" here's some things that I really want to look at in this offseason," Zimmer said on Tuesday. "There's some other teams I want to study that have done a good job. I want to go back and evaluate a lot of our rush situations to see if we can improve in some of those areas. Go back and see why we were good on third downs. Our job as coaches is to, number one, put the players in the best position possible to win. Number two, to try to continually get better, figure out new ways to do things. I think that's how you come up with new concepts, new ideas, new ways to attack offenses."

The coach said after Sunday's 38-7 loss that the Eagles had found ways to attack some of the Vikings' strengths, and that was evident perhaps in no area more than Philadelphia's performance on third downs. The Eagles converted 10 of their 14 third-down attempts, against a defense whose third-down percentage (25.2) was better than any in the league since the NFL began tracking the statistic in 1991.

It started in the first quarter, when the Vikings showed a seven-man front and sent five rushers after Foles on 3rd-and-11, with right end Everson Griffen and linebacker Eric Kendricks dropping out while Harrison Smith blitzed off the left side. Eagles running back Corey Clement stepped from Foles' left to his right, picking up Smith's blitz and creating a clean window for Foles to hit Zach Ertz between Griffen and Trae Waynes. Ertz broke Waynes' tackle and got the 11 yards he needed for a first down.

Foles had time for a hard pump fake before hitting Ertz for 15 yards on 3rd-and-8. He found Jay Ajayi for eight yards on a 3rd-and-6 in the second quarter, and later on the drive, he slipped away from Everson Griffen's attempt to strip the ball, unleashing a 53-yard strike to Alshon Jeffery, who'd separated from Terence Newman after Xavier Rhodes left with a toe injury.

Execution might have led to some of the Vikings' problems on Sunday night, but Zimmer planned to look first at his own role in what happened.

"I mean, not only them, but anybody that had success against us in the past," he said. "I think one of the things I meant was that we'd been great at third downs and they got after us on third down. So, we need to figure out, 'Okay, why were they and how could we do this?'. That's why I said I could have made some better calls. Sometimes when you're sticking with things and it's been successful for you, you continue to do it and maybe I did it a little bit too long. That's all a part of the process of self-scouting, evaluation, and things as you go forward."

Most of the Vikings' defense will return intact in 2018, and the team will likely add to its group in the offseason, with more than $50 million in free cap space and a first-round pick. But while the group figures to be the strength of the team again in 2018, its quest to improve will undoubtedly be colored by what the Eagles did on Sunday night.