Sam Bradford said he's enjoyed the up-close view of the Vikings defense this season but facing the unit would be a different story.

"Well, fortunately for me, I don't have to play against those guys, because they're playing great right now," Bradford said. "I think they're probably playing some of the best defense in the NFL right now. It's a lot of fun to watch them on Sundays when they go out there and take the field, because they play hard, they play physical. Obviously, they're just playing really well right now, and it's good to know we have those guys on our side."

Bradford could have happened this week in Philadelphia had the Eagles not traded him to the Vikings on Sept. 3.

Bradford spent the whole offseason with the new Eagles coaching staff and rookie Carson Wentz, who will start against the team that he fervently followed while growing up in North Dakota.

Eagles Offensive Coordinator Frank Reich wasn't being hyperbolic when he talked about the expected difficulty of Sunday's matchup between Vikings Head Coach Mike Zimmer's 5-0 squad and the 3-2 Eagles.

"When you go up against a Coach Zimmer defense, it's always the biggest challenge of the year," Reich told members of the media in Philadelphia this week. "They are so well-coached, very disciplined, fast, a good challenge for us this week, great schemes, very well-coached and good personnel, so we have our work cut out for us."

Reich was Chargers offensive coordinator last season when the Vikings sacked Philip Rivers four times, recorded 13 quarterback hits, limited San Diego rookie Melvin Gordon to 51 yards on 14 carries and finished off the day with a 91-yard interception return for a touchdown by Chad Greenway.

Reich said a calling card of the Zimmer defense is pressure-packed looks pre-snap, often by bringing Anthony Barr and Eric Kendricks down to front the A gaps on each side of the center and a variety of tactics deployed during plays.

"Everybody runs the double-A gap system, but in my mind, Zimmer is the master of it. It's his baby," Reich said. "I don't know — he probably didn't invent it, but he's mastered it. They run every kind of combination there is known to man, and they know — what takes it to a different level is they know what you're trying to do. They know what teams have done to try to counter it.

"It's a cat and mouse game that you play," Reich added. "We have our things that you try to plan to do to it, and we'll do, but you can't do the same things every time because they're making in-game adjustments to what you're doing; we're making in-game adjustments to what they're doing. Sometimes you're going to hit it right, and we'll get the big play; other times we tell our guys, 'Hey, they might get us once or twice. You play this team, they might get you once or twice, you've got to get back up off the canvas and get in third and manageable or punt the ball. Don't turn it over, and let's keep playing ball.' "

Eagles Head Coach Doug Pederson, a former NFL quarterback like Reich, said he's also concerned with the amount of pressure that Minnesota has placed on teams, particularly with its defensive line.

"Obviously, they've got a tremendous pass rush. It starts with the defensive line, 19 sacks and 17 of them coming from that group," Pederson said. "It's an explosive group. Gosh, they pride themselves in getting off the ball. They time themselves in getting off the ball, they time the snap count up extremely well. Then, they favor in second-and-longs and third-and-longs. That's where they want to get you. That's when they're at their best. Coach Zimmer does a great job with his blitz packages and when to bring them and the timing of the blitzes. It's a fast defense. They're good and undefeated because of that. That's a credit to the coaches and players in Minnesota."

Here are highlights from what the Eagles said about the Vikings during other media sessions this week:

Wentz on the Vikings defense:

"The first thing that sticks out is that they play fast. They play very confident and you can just tell on film that they're well-coached. They fly around, they like to make plays. We have to be sharp. We have to execute and play disciplined football, and that's something that's gotten away from us these last couple weeks. We've had a lot of penalties and mistakes in that area so we just have to play smart, play fast and do our assignment."

Eagles safety Malcolm Jenkins on facing Bradford:

"It's weird to, you know, a few weeks back, Sam was getting ready to be our starting quarterback, and now we're getting ready to play him. He knows a lot about us, and we know a lot about him, so it will be fun to get to play against him.

"One thing we know all too well is that he can sling the ball, especially when he's upright and comfortable. He can make all of the throws," Jenkins added. "He's savvy enough to look off safeties. He can manipulate coverage with his eyes and he knows his playbook. He knows where his check-downs are, so he's a smart, bright quarterback with a live arm. We're going to have to show up."

Eagles Defensive Coordinator Jim Schwartz on the Vikings offense:

"You look at the success, their numbers aren't going to boggle you offensively with the exception of turnovers. They have one turnover on the year. No interceptions, and that goes a long way. You look at their stats across the board, they're not rushing for a very big average. I don't know if you'd expect that, with losing Adrian Peterson, but the quarterback is completing a lot of passes, a real high completion percentage. They're not afraid to take the check-down.

"They haven't made many mistakes, and as well as their defense is playing, that's been a good formula for those guys," Schwartz added. "We've got to find a way to take their security blankets away, make them more aggressive in attacking the defense and also make them play from behind."

Schwartz on defending Kyle Rudolph:

"I think the challenge this week is [Vikings tight end Kyle] Rudolph. He might not be their leading receiver, but he's a security blanket for the quarterback."