Mike Zimmer fired an offensive coordinator only 13 games after he hired him because he didn't run the ball enough. Once, Zimmer called for a two-point conversion in a huff after his rookie kicker missed one field goal. In a preseason game.

Patience doesn't rank high on Zimmer's list of coaching strengths. He expects things to be done a certain way. Except, 2020 doesn't follow anyone's script.

This season already has careened outside of Zim's diagram for how he prefers things to operate. The Vikings head coach will need to locate a reservoir of patience and adaptability to avoid going completely bonkers.

First, the uncontrollable. Or largely uncontrollable.

The events of last week revealed the tenuous nature of the NFL's attempt to play this season during a pandemic outside of a secured bubble.

An outbreak of coronavirus positives in the Tennessee Titans locker room also created disruption for their most recent opponent. The Vikings were forced to evacuate their facility one day, skip one full day of on-field preparation and institute additional intensive safety protocols and measures the remainder of the week.

Coaches hate distractions. Trying to keep the virus at bay is a lifestyle more than a distraction, and the NFL's first major outbreak created an extra layer of concern and complications that shifted hypotheticals to reality.

Thankfully, the Vikings have avoided their own outbreak after being exposed to the Titans. For now, at least. If the team continues to report no positive cases through Sunday, the Vikings will have earned its first win of the season.

Zimmer told his team that the schedule interruption provides no excuses for how the Vikings perform Sunday in Houston. That's according to General Manager Rick Spielman, who relayed Zimmer's "no excuses" message to reporters. Zimmer responded by noting that his boss shouldn't share what he tells his players with reporters.

Spielman didn't exactly give away trade secrets, but an 0-3 start has made his coach a little cranky.

Zimmer boasted before the season that "I've never had a bad defense." His defense currently is one of the NFL's worst. The Vikings rank 31st out of 32 teams in scoring defense, allowing 34 points per game. They are giving up 440 yards per game, third worst in the league.

Zimmer dreams at night about winning games 13-10. A few years ago, the Chiefs and Rams shot off offensive fireworks in a game that ended with a 54-51 final score. Zimmer grumbled, "It's not my cup of tea. Might run me out of football."

His visual blueprint needs tinkering. Maybe not 54-51, but low scoring isn't realistic right now.

Zimmer would rather gargle vinegar than accept a football track meet, but his team will need to win shootouts to have a chance this season, at least until his defense can A) get healthy and B) get more experience.

According to ESPN, the scoring average has skyrocketed to 24.7 points per game — a 22% increase from Weeks 1-3 over the previous two decades. That substantial increase is due in large part to a sharp decline in offensive holding penalties, which likely isn't helping Zimmer's mood.

Zimmer has publicly challenged his veteran offense to take charge in critical situations. In other words, his defense is vulnerable. That side looks overwhelmed in trying to hold offenses in check.

Zimmer's defense already faced a steep curve with roster turnover in the secondary. Relying on rookies and inexperienced cornerbacks in today's NFL basically invites tough times.

Nose tackle Michael Pierce, the prized offseason addition, opted out for health reasons. Then take away Danielle Hunter, who clearly had more than a "tweak" since he's still sidelined by injury, and Anthony Barr, their defensive signal-caller and second-best linebacker who is out for the season.

This is not what Zimmer envisioned. He sounded exasperated after witnessing two clunkers and one late meltdown.

The Vikings found a formula last week that makes sense. Feed the ball to Dalvin Cook, Justin Jefferson and Adam Thielen and hope to score a lot of points — enough to compensate for a bad defense.

Zimmer might hate the way that plan sounds, but this is their new normal.

chip.scoggins@startribune.com