MINNEAPOLIS -- The Minnesota Vikings will walk away from 2020 with several hard-learned lessons, many of which they've already come to realize following a 33-27 loss to the Chicago Bears on Sunday that squashed their playoff hopes.

A lot of what has been discovered isn't anything new. But to fully understand the Vikings' North Star, you need to go back to the day after the 2019 season ended in the divisional playoffs.

The Vikings got off to a fast start against the San Francisco 49ers behind a Stefon Diggs touchdown and then didn't go to the receiver again. Minnesota's staunch rushing offense mustered 21 yards. No change was needed, especially on offense, according to coach Mike Zimmer. Even though the Vikings knew they wouldn't be the same defensively with all the pending departures, they decided to run back what they did last season in 2020. And it didn't work.

The Vikings have been in the postseason three times during Zimmer's seven-year tenure, and it would take an all-out miracle for that to happen a fourth time this season. A level of inconsistency from one year to the next has become routine in Minnesota. And the failure to sustain success year to year doesn't seem to convince the Vikings that a change in decision-making or philosophy is in order.

Minnesota will soon be in offseason mode, preparing to right its wrongs from a year of ups and downs. Here's a couple of lessons the Vikings should be aware of entering the final two weeks of the season.

Set manageable, realistic expectations

The self-assured hubris of the Vikings' defense was met with a firm reality check. Zimmer's scheme, no matter how good it has been in the past, could not account for players who were unfit to assume major roles. Zimmer repeatedly talked about this year as the most challenging coaching job he and his defensive staff have ever faced. An experience like that likely will be something they can build on in 2021, starting with the reality that they can't just plug in young, inexperienced players in and expect the group to look like the one that boasted multiple Pro Bowlers and top-10 rankings in points allowed over the past five seasons.

But there are signs of promise. Cameron Dantzler is the NFL's highest-rated rookie cornerback, according to Pro Football Focus, overcoming injuries and the ups and downs of a first-year player in a complex defense. Fellow rookie cornerback Jeff Gladney has potential, as does defensive end D.J. Wonnum. But this unit needs an upgrade at several positions (including cornerback) through free agency and the draft if it wants to play at the level it once did.

Offensive and defensive lines need work

Yannick Ngakoue, whose brief stint in Minnesota ended after Week 6 when he was traded to the Ravens, could end up being the Vikings' sack leader (5.0) for 2020. The Vikings failed to generate much of a pass rush or stop the run (the Bears made rushing for 199 yards look easy in Week 15). Part of that could soon be remedied, assuming nose tackle Michael Pierce plays in 2021 after opting out this season. But Minnesota needs to use a high draft pick on a three-technique defensive tackle to generate the interior push that was lacking this season. With some uncertainty about Danielle Hunter coming off neck surgery, it would also be wise to inquire about some help at edge rusher.

In what has been a broken record for years, the Vikings failed to protect quarterback Kirk Cousins or fix the issues they've had on the interior of the offensive line. They learned the hard way that Dakota Dozier and Dru Samia are liabilities. Unless general manager Rick Spielman change his tune about going after guards in free agency or early in the draft, don't expect things to get much better. The Vikings are 1-7 when allowing pressure on at least 30% of Cousins' dropbacks this season (including 40% in Weeks 14-15) and 5-1 with less than 30% pressure. Cousins has been pressured on 38% of dropbacks in losses this season, the fourth-highest rate in the NFL (25% in wins, 24th in the NFL).

Diggs gamble paid off

The Vikings' decision to trade Diggs to the Buffalo Bills and draft Justin Jefferson with the first-round pick they got in return worked out well. On Sunday, Jefferson broke Randy Moss' rookie record for receptions (69; he now has 73). He is 131 yards away from surpassing the franchise's rookie receiving record (1,313), also set by Moss.

Need increased sense of urgency

Jefferson, 21, and running back Dalvin Cook, 25, are young superstars. The Vikings cannot waste another big season from either by not having the players around them to be competitive. The front office and coaching staff should feel the pressure to get the most out of these two in 2021.

Don't get stuck on the run

The Vikings fulfilled the promise Zimmer made to be a run-first team. But that often made them easy to figure out. No other team ran the ball more on second down (47.6%) than the Vikings, who also had the fifth-highest designed run percentage. Sticking with the run regularly while trailing in the second half of games often put the Vikings in a position to run the clock out on themselves. Take for instance Minnesota's second touchdown drive in Tampa Bay in Week 14 and the decision to run against Chicago while trailing by 10 on Sunday. Even with star receivers in Jefferson and Adam Thielen, the Vikings' insistence on running the ball played a role in them coming up short.

And the oft-used justification that defenses are taking away Cousins' chance to find Thielen and Jefferson was debunked by the quarterback in Week 15.

"We still devote a lot of our plays to running the football," Cousins said. "So the number of times we're handing the ball off and doing so fairly effectively, those just are plays where we're not taking that opportunity to take a shot downfield."

That's not acceptable. The best offenses in the NFL are the ones that give their best playmakers a chance to break the game open. The Vikings didn't do that consistently, especially in their two-minute offense with Cousins, who was more likely to go to his running back and tight ends than his receivers.

Zimmer favors a methodical offensive approach that caters to the way he wants to win -- with defense. Conservative and sometimes baffling play calls (take the dead-end, third-and-1 and fourth-and-1 calls on Minnesota's second-to-last possession against the Bears) cost the Vikings when they should have trusted Thielen or Jefferson.

That's a mistake they can't afford to make again.