In the middle of October, Mike Zimmer is looking for proof that his one-loss Vikings team is special.

That’s what Sunday’s 21-10 beatdown in Philadelphia did to the NFL’s last unbeaten team. The Vikings’ shortcomings on offense, which at one point against the Eagles accounted for more turnovers (four) than points (three), exposed them as a team with some potentially crippling flaws.

Even as Zimmer tries to pick up the pieces, the good will built during a five-game winning streak has dissolved as they prepare for the Chicago Bears next Monday night at Soldier Field.

“I do have faith in this football team and obviously, you know, faith is belief without proof,” Zimmer said Monday. “Right now, I don’t have any proof, so I have to have faith that we’ll get it done. I think we will. But until we prove it, it’s just throwing stuff against the wall.

“We’re trying to figure out everything right now. This is a gut-check day.”

Zimmer verbally sorted through the reasons for the letdown loss, stopping on many “uncharacteristic” and “dumb” mistakes, including penalties in the red zone, special teams woes and receivers not getting out of bounds to save clock near the end.

One issue has grown notoriously characteristic: keeping quarterback Sam Bradford upright. The Vikings’ most glaring weakness should take priority as coaches convene this week inside Winter Park.

Jake Long, T.J. Clemmings and Jeremiah Sirles, the rotating trio at the injury-thinned tackle spots, were exposed against the Eagles. They were routinely beaten and responsible for all four strip-sacks on Bradford.

The coaching staff also needs to better help struggling players in pass protection, according to Zimmer. The salary cap-strapped Vikings, with millions on injured reserve, can’t afford to add any more reinforcements, as if many good options are available in October, anyway.

“I pride myself on knowing protections,” Zimmer said. “So I’ve got a pretty good idea on protections and how to help it. We’re going to see what we can do.”

Blame could be spread around the huddle at Lincoln Financial Field. Linemen and backs were porous in blocking for Bradford, who took a season-high 18 hits (six sacks) against the blitz-happy Eagles. Dropped passes, inaccurate routes and penalties further exposed issues up front.

As the hits piled up, Bradford was quickly thrown off. A hot start in Minnesota, including six touchdown passes and no interceptions in four starts after Philadelphia traded Bradford last month, felt like a distant memory as Eagles defenders boasted after the game about knowing how to attack their former teammate.

“Some of it was getting the protection turned the right way. Some of it was getting beat one-on-one,” Zimmer said. “Sometimes it was not getting the ball out. It looked like [Bradford] made a bad throw on the over route to [Stefon] Diggs. Well, Diggs was 10 yards short on the route.”

Zimmer has navigated rougher waters in his 2 ½ seasons with the Vikings. He recalled the first loss of last season, which at the time gave him a 7-10 record as head coach. The Vikings responded by winning seven of their next eight games.

“We had a pretty tough loss in San Francisco last year and we fought back,” Zimmer said. “I’m anxious to see the determination this team has going forward. You never know, every team is different. But I think I have a pretty good feeling with these players, typically, and with this football team.”

Resiliency is a buzzword often echoed off the Winter Park walls. After a reality check, they have an opportunity to prove they are what everybody thought they were before the debacle in Philadelphia.

Zimmer has a plan for that in the works.

“We’re going to change some things up this week,” Zimmer said. “They don’t know yet, so I’ll just let ’em figure it out.”