MINNEAPOLIS -- Perhaps the sternest test of Mike Zimmer's ability to remake the Minnesota Vikings' defense will come in an 18-day stretch from Sept. 14 to Oct. 2, when the Vikings will play four consecutive games against Tom Brady, Drew Brees, Matt Ryan and Aaron Rodgers, effectively staking their playoff hopes on their ability to stand up to some of the best quarterbacks in the NFL.

In many ways, the Vikings will have to fix two of their biggest problems from last season in the first month of the season if they're going to have any shot at relevance. They didn't win a road game last season (their victory in London was technically a "home" game), and they'll start the year against a St. Louis Rams team that went 5-3 at home last season before playing games at the Superdome and Lambeau Field in the next five weeks.

Mike Zimmer's defense made things challenging for Aaron Rodgers last season. AP Photo/David Kohl

But the Vikings' struggles against top quarterbacks, if left unchecked, will be an even more pervasive problem in the first part of the season. The Saints, Packers, Falcons and Patriots were the league's second-, sixth-, seventh- and 10th-best passing teams last season, and the Vikings come out of that stretch with an Oct. 12 game against the Detroit Lions, who threw for the third-most yards in the league. Essentially, the message of the Vikings' 2014 schedule is this: Fix your defense and fix it quickly.

Fortunately for the Vikings, Zimmer's had some success slowing down the quarterbacks the Vikings will face -- particularly Rodgers. The Packers quarterback faced the Cincinnati Bengals twice while Zimmer was their defensive coordinator, and lost both games. Last year, he hit 26 of 43 passes for 244 yards, a touchdown and two interceptions against the Bengals, and was sacked four times. And while he threw for 311 yards against the Bengals in 2009, he was sacked six times and fumbled twice (losing one) in a 31-24 loss.

Brady also faced the Bengals twice in that time, with unimpressive results. He went 1-1 in a pair of games against Cincinnati, completing 43 of his 73 passes for 455 yards, three touchdowns and an interception. After picking them apart in a 2010 win, he had arguably his worst game of the season against them last year, completing just 18 of his 38 passes for 197 yards and an interception in a 13-6 loss.

Brees and Ryan both fared well in their lone efforts against Zimmer's defense, each beating a 4-12 Bengals team in 2010. They were two of just four quarterbacks to surpass 290 yards against Cincinnati that season, posting 313 and 299, respectively.

Zimmer's defense employs plenty of man coverage, mixed with some zone principles, and counts more heavily on cornerbacks winning one-on-one matchups than the Vikings' old scheme did. That seems like a good fit for second-year cornerback Xavier Rhodes, and Captain Munnerlyn should help the Vikings' defense, as well, but secondary depth is paramount to surviving matchups with teams that will put as many receivers on the field as the Vikings' early-season opponents will.

The other thing to watch is how effectively the Vikings can pressure the top quarterbacks they'll face, particularly with some of Zimmer's creative blitzes. The Bengals didn't bring extra pressure after Brady and Rodgers all that often last year -- on just 12 and 11 dropbacks, according to ESPN Stats & Information -- but what's worth noting is just how much they rattled those two quarterbacks. Brady had just a 2.2 QBR against the Bengals' blitzes last year, and Rodgers' QBR was only 8.0, as he was forced into checkdowns and didn't complete a pass of longer than 8 yards against the blitz. Considering how lethal those two quarterbacks have been against the blitz in their careers -- to the point where many teams don't try to send extra pressure -- Zimmer's ability to throw them off is impressive. He did it well against Matthew Stafford last season, too, holding the Lions quarterback to just 33 yards and a 5.0 QBR on 13 blitzes.

The key variable to all this, of course, is talent, and it remains to be seen if the Vikings' personnel is as effective in Zimmer's scheme as what the Bengals had last season. But the additions of Munnerlyn and defensive tackle Linval Joseph, the development of Rhodes and defensive tackle Sharrif Floyd and the health of safety Harrison Smith should help. If Zimmer and defensive coordinator George Edwards can coax more out of players like defensive end Everson Griffen and figure out the Vikings' linebacker situation, they'll likely receive credit for it early, because the Vikings' progress will be graded against some of the toughest opponents they'll see all season.